Flash bang devices were used to distract protesters as police moved to clear them out of Hamilton Hall, according to media reports quoting New York police.

The devices were used to "disorient protesters as police made their way inside", said news site CBS, adding that no tear gas was used.

One student the BBC spoke to said "about 80 - 100 police officers" had stormed the building.

Protesters had take over the Hamilton Hall building early on Tuesday, amid two weeks of campus protests over the Israel-Gaza war.

This video released by the NYPD shows officers crowding the narrow staircase inside the building and removing barriers like chairs.

Alex Lederman
Reporting from Columbia University

I was in the middle of interviewing a student who had been at Hamilton Hall earlier tonight when an officer interrupted, shutting the windows so she could no longer talk to me.

She had just been describing how police had manhandled students during arrests, including pushing people down stairs.

"There was someone unconscious on the floor getting arrested and then they were pulled away while they were unconscious."

"Three people were pushed down the stairs by the NYPD".

Earlier she had been at Hamilton Hall when "about 80-100" police officers stormed the building, adding that they had driven many protesters out to another building - a residential hall - on campus.

"They barricaded the doors and had about 2 or 3 offiicers stationed in each door so we couldn’t get out -which is illegal in its own," she told me.

We'll have the whole video interview for you to see shortly.

Bernd Debusmann Jr
US Reporter

Image source, Getty Images

Democratic New York representative Alexandria Ocasio-Cortez said that "responsibility will fall" on New York Mayor Eric Adams and university presidents "if any kid is hurt tonight".

In a post on X, formerly known as Twitter, Ocasio-Cortez said that "other leaders and schools have found a safe, de-escalatory path."

"This is the opposite of leadership and endangers public safety," she wrote. "A nightmare in the making. I urge the mayor to reverse course."

Alex Lederman
Reporting from Columbia University

A row of police still guard the front entrance to Columbia University, but the scene has calmed.

Over the past three hours, buses filled with protesters have driven by, and chanting students and media have gathered.

The standoff escalated when the university's president, Minouche Shafik, told students to clear the encampment on the lawns of the university by Monday afternoon.

Protesters did not, and their fellow students and faculty guarded the encampment’s entrance.

But overnight, students seized Hamilton Hall and renamed it Hind's Hall - after a six-year-old Palestinian girl killed in Gaza in February.

After a day in which the campus was mostly blocked off, police entered on Tuesday night and began making arrests. They marched out those they had detained and loaded them onto buses.

Protesters cheered as buses filled with them drove by. They chanted “Shame on you” and “Quit your job” to police.

John Sudworth
North America Correspondent

Image source, Getty Images

Just south of the campus, to shouts of "shame", the police moved into the small crowd that had gathered and cleared the road.

Then the last bus of arrested student protesters was driven out, met with cheers and whistles.

Some of the crowd moved forward banging on the side of the bus, but they were quickly smothered by the police who pulled them to the ground and marched them away.

Shallow crowds remain on the periphery of the cordon, occasionally shouting at the police. And every now and again a scuffle has broken out between pro and anti-protesters, but each time it has been swiftly dealt with by the police.

The New York Police Department have confirmed to the BBC that all protesters have been moved out of Hamilton Hall - the campus building they had taken over 24 hours ago.

They did not tell us how many people have been arrested, but US outlet NBC is reporting that up to 100 people have been detained so far.

Quoting an NYPD spokesperson, CNN just reported that the force has also cleared the nearby protest encampment on Columbia's lawn.

No injuries were apparently reported during the clearance operation.

It is unclear how many people have been arrested, although the spokesman and journalists at the scene have reported that the figure is in the dozens.

One of the student negotiators who has gained prominence in recent days, Mahmoud Khalil, told CNN he believes that student protests will continue in some form.

New York police have just raided a Columbia University hall to clear out pro-Palestinian students who had barricaded themselves inside.

• The activists had taken over the Hamilton Hall building nearly 24 hours earlier amid two weeks of campus protests over the Israel-Gaza war

• About 50 students were arrested and moved out of the building, US media report
• Live footage showed a long line of police in riot gear climbing into the building through a second-storey window, using ladders
• Other officers spread across the campus, holding back crowds of other protesters and onlookers, some of whom chanted: "Shame, shame!"
• Officers were seen leading handcuffed protesters to police buses outside the gates of the Ivy League campus in upper Manhattan

• Columbia students have been protesting against their university's investments with Israel, and had draped a banner over the building renaming it Hind's Hall after a six-year-old Palestinian girl, Hind Rajab, who was killed in Gaza in February

• University administrators had previously threatened expulsion of the students in the building
• Columbia University has been the focal point of student protests over the war - the demonstrations have spread to universities across the country in the past fortnight and hundreds have been arrested

Image source, Reuters

Bernd Debusmann Jr
US Reporter

Columbia's student newspaper, the Columbia Spectator, has said that "dozens" of arrests were made during tonight's NYPD operation to clear Hamilton Hall.

According to the paper, officers began their operation at 9.30pm local time, "pushed protesters to the ground" and "slammed them with barricades".

The newspaper also reported that some protesters had attempted to form a "human chain outside the doors" of the hall, only for police to throw "down the metal and wooden tables" and shatter glass doors before entering the building "with shields in hand".

Images from Columbia show protesters being arrested and put on a police bus to be taken to the station for processing.

Several can be seen wearing keffiyehs, the Arabic scarf worn by pro-Palestinian protesters.

Other protesters who have not been arrested cheer for them as they are brought out.

Nomia Iqbal
BBC News, Columbia University

The scene outside remains chaotic, as the arrests continue.

We've seen several NYPD buses leave the scene, most probably filled with protesters.

CBS News, the BBC's partner in the US, reports that there have been around 50 arrests so far.

There are huge cheers of support by anti-war protesters as the arrested students are marched off with their hands in zip ties.

One man tells me the arrests have brought shame to the city.

Image source, Getty Images

Columbia was the first university to see a large camp form on campus in opposition the Gaza war.

The site rapidly grew in size on April 18, one day after the university's president testified to Congress about antisemitism on campus.

The university sent police in, citing "a harassing and intimidating environment for many of our students". More than 100 protesters were arrested.

Dozens of sympathetic protests then began to pop up at other US universities.

On campuses in Texas, California, Georgia, North Carolina, Utah, Virginia, New Mexico, California, New Jersey, Connecticut and Louisiana, police have arrested more than 1,000 protesters.

But other universities have taken a different approach, and let the protests continue unimpeded.

Donald Trump was just on Fox News, decrying a "sad day" at Columbia and arguing that authorities "must get to the roots" of antisemitism.

In a brief phone interview, Trump said "Biden has to do something. He's got to strengthen up and be heard."

"It should never have gotten to this," he added. "They [the NYPD] should have done it a lot sooner than when they took over the building."

His comments came hours after President Biden condemned a "ferocious surge of antisemitism" in the US.

"It is our shared moral responsibility to forcefully stand up to antisemitism and to make clear that hate can have no safe harbour in America," he added.

Image source, Getty Images

The letter that the president of Columbia, Nemat Shafik, wrote to the NYPD requesting the raid has been obtained by US media.

In the letter, Shafik says the occupation of Hamilton Hall began after a group of "students" entered the building with the purpose of taking it over.

One "individual" hid in the building until it was closed, then opened doors to let other protesters in, she says, adding that the action was "led by individuals not associated with the university".

"The individuals who have occupied Hamilton Hall have vandalized university property and are trespassing," Shafik wrote to police.

She said she was able to secure the release of two security guards caught inside when the occupation began.

Shafik goes on to say that protesters have been suspended. She adds that the protests have become a "magnet for protesters outside our gate" and created an dangerously unsafe situation.

She says "with the utmost regret" she requests the police raid.

New York police sent dozens of officers into Hamilton Hall, the occupied Columbia building, after setting up a ramp. Here's the video of the moment they moved in.

Don't forget - you can also see live coverage from the scene by clicking the play button at the top of this page.

Columbia's student radio station has reported that a New York police bus has arrived just off the campus, at the corner of 116th Street and Broadway, to transport people taken into custody during the protests.

Images being broadcast on US TV networks show protesters - many of them wearing Columbia-branded sweatshirts and other items of clothing - entering similar buses.

We still don't know how many students have been arrested.

A police official just said on CNN that officers have used flashbang grenades, but not teargas, during tonight's operation.

Bernd Debusmann Jr
US Reporter

New York Democratic congressman Jamaal Bowman has condemned the police operation at Columbia, saying he is "outraged by the level of police presence" at the school.

Bowman - a former teacher - said that "education institutions should be spaces to nurture critical thinking skills and learn to work together with diverse communities to enact a more just and peaceful world".

"The militarisation of college campuses, extensive police presence, and arrest of hundreds of students are in direct opposition to the role of education as a cornerstone of our democracy," he added.

In his statement, Bowman also called on Columbia to "stop this dangerous escalation before it leads to further harm" and to allow faculty back on to campus to help negotiate "a solution that centres humanity over hate".

Image source, Getty Images

You can click on the play button at the top of this page to watch a live feed from the grounds of Columbia University.

We're seeing that police have set up a staircase ramp outside the building to reach the second floor and move in through the windows.

Protesting students had barricaded themselves inside Hamilton Hall

Image source, Getty Images

Image source, Getty Images