Orlando's mayor Buddy Dyer said "hundreds of lives were saved" as he praised the work of the FBI and emergency and medical teams at the Orlando nightclub.

He said 48 victims have been identified, and that 24 next of kin have been notified. 

Orlando Mayor Buddy Dyer is providing an update on the investigation.

BBC Monitoring

So-called Islamic State (IS) has issued a second message linking the Orlando nightclub killer to the militant group, while still offering no details or new information to support the alleged affiliation. 

IS's Al-Bayan radio bulletin for Monday led with news of the attack, attributing it to "one of the caliphate's soldiers in the US". 

The brief news item said the assault was the biggest in the US in terms of casualty numbers since the 9/11 attacks.

A first IS claim was made on Sunday by the group's self-styled news agency Amaq, which simply attributed the attack to an IS "fighter". 

IS commonly issues brief claims on attacks via Amaq and subsequently Al-Bayan radio - rather than releasing a statement through its central media arm Nashir - in cases where the group does not appear to have been directly involved in planning the attack.  

You can read more about the attacker here.  

A news conference is expected to begin in Orlando in the next few minutes. Police had been due to provide the latest update at 07:00 (13:00 GMT). 

Shares of the British private security company G4S had losses of more than 5% on the London Stock Exchange this Monday, following news Omar Mateen, the gunman behind the Orlando shooting, was one of its employees.

The company issued a statement, external saying: 

Mayor of Paris Anne Hidalgo tweets that the Eiffel Tower will pay tribute to the victims later.

Afghanistan's Chief Executive Abdullah Abdullah told the country's cabinet that the Orlando shooting "tells us that terrorism knows no religion, boundary and geography. Terrorism must be eliminated."

He added that Afghans "do not support terrorism but the victims of terrorist attacks'' and offered his condolences to the people and government of the United States.

He also urged "collective actions to end such attacks".

The gunman, Omar Mateen, was a US citizen of Afghan descent. He was born in New York and lived in Florida, and was not on a terrorism watch list. 

Image source, AFP

US President Barack Obama has ordered, external the country's flag to be flown at half mast until sunset on Thursday in honor of the victims of the Orlando shooting.

The order applies to the White House, public buildings and grounds, military posts, naval stations and vessels, embassies, consular offices, legations and others facilities throughout the US, its territories and abroad.

Here are some of the front pages of US newspapers and how they are covering the shooting in Orlando.

Image source, EPA

Reacting to the shooting in Orlando, German Chancellor, Angela Merkel, has said: "We have a heavy heart [over the fact that] the hatred and malignancy of a single person cost over 50 people their lives."

Mrs Merkel, who on a visit to China, added: "We are firmly determined, even when such murderous attacks put us into deep sorrow, to continue with our open, tolerant life."

Japanese prime minister, Shinzo Abe, has joined the international condemnation of the Orlando shootings, saying such acts of terrorism should not be tolerated. He said Japan "stands together with the people of the United States" and expressed his country's "strong solidarity" with the US and its people.

The Orlando nightclub attacked on Saturday, Pulse, has shared on its Facebook page, external a link to a fund raising for the victims and families, external of the shooting.

It was set up 19 hours ago and has already raised $1.3m (£920,000). The goal is to raise $2m (£1.4m).

David Sotomayor, whose cousin Edward died in the attack, says the LGBT community must "stand strong and be proud".

The Orlando Sentinal newspaper has explained the reasons behind the front page of its Monday edition. It featured a headline stating "Our community will heal". It says the paper "needed to reflect what we were hearing throughout Sunday" about the shootings at the Pulse nightclub.

"Many talked of the sadness that we were now the leaders on an infamous list of mass shootings in the United States. But also we heard a growing chorus throughout the day that this horror would not be how we are remembered. 

"'Let our community define itself by our unequivocal response: United.'

"Those are the key words in our front page statement in Monday's Orlando Sentinel newspaper. We published it with a photo of a pair of people in a sorrowful embrace."

You can read the paper's front page editorial here, external.

BBC Monitoring

Russian Foreign Ministry spokeswoman, Maria Zakharova, has called for "empathy" for the victims of the Orlando shootings. 

Writing on her Facebook page, external, she criticised posts by some Russian internet users, saying: "Comments such as 'we don't feel sorry for the Orlando dead, because they are gay' are simply disgusting." 

She said "it is impossible to stand up for even the most correct traditional values if you have no empathy."

London's LGBT community will hold a vigil in tribute to the victims, external at the city's famous Soho district.

Venues at Old Compton Street, at the heart of London’s gay village, will stop serving at 19:00. People will then be invited out onto the streets to pay their respects, organizers say. 

BBC Monitoring

An editorial by French journalist Jean-Marie Montali in Aujourd'hui en France newspaper - the national edition of Le Parisien - says the "Orlando killer reminds us of those who struck in Paris, Brussels and just last week in Tel Aviv".

He writes: "The same immense cowardice, the same mental perversion that involves experiencing the murder of innocents in a country at peace as an act of heroism."

There has been a huge number of people reacting to the shootings on social media sites, including people from Orlando's gay and Muslim communities.

Image source, AP

The attack at the Pulse nightclub was the deadliest on US soil since the 9/11 attacks. 

The New York Times has broken down why the death toll was so high, external. The club was loud and crowded, it says, so people didn't know immediately what was going on.

Mateen was also actively shooting for three hours before he was killed, meaning some of those initially injured may have died before getting help. 

Finally, he was using a high-powered but legally bought assault rifle. These are designed to kill as many people as possible in as short a time possible. 

Image source, Reuters

So far, 21 victims have been named, external: 17 men and four women. Their ages range from 20 to 50 years-old.  

They include:

• Edward Sotomayor, 34, who worked for a company that organised gay cruises;
• Stanley Almodovar, 23, a pharmacy technician who was remembered as "kind and sassy";
• Kimberly Morris, 37, who had only recently moved to Orlando and worked at Pulse as a bouncer;
• Luis Vielma, 22, who worked at the Harry Potter section at Universal Studios - author J K Rowling paid tribute to him online, external;
• Eddie Justice, 30, who sent his mother a series of text messages while inside the club - read more on him here.