What looks like a removal truck has arrived at the scene.

It was waved through the police cordon and is now parked outside Parliament.

Image source, PA

A witness has described seeing a car drive into a barrier "at speed" at the Houses of Parliament.

"In my opinion it was deliberate," said Jason Williams, who was in Westminster at the time of the crash.

The crash occurred in central London outside the Palace of Westminster. Parliament is not currently sitting.

A witness said the vehicle was travelling westbound when it swerved into eastbound traffic.

Dominic Casciani
Home Affairs Correspondent

Security arrangements at Parliament have progressively tightened since 2001. In the aftermath of the 7/7 attacks, new truck bomb-proof barriers were installed in an effort to "target harden" Westminster. These include the reinforced low black rampart-like walls that surround Parliament itself and a highly visible armed police presence.

Visitors need to go through a chicane-like system designed to help armed officers spot suspects. The one significant weak spot was the main vehicle gates - as became apparent in March 2017's one-man attack.

That triggered an internal security review that has led to changes that remain secret - although it's apparent to Londoners that there are now more armed police than ever before patrolling the area.

The threat of terrorism is a constant concern for Parliamentarians - it's not new. The IRA murdered Airey Neave MP in 1979 in a car bomb that exploded within the palace grounds. And the dilemma remains the same: how best to balance security with guaranteeing that the heart of British democracy remains open to the people.

Image source, PA

One woman is being treated in hospital for serious but non life-threatening injuries following this morning's incident.

A spokeswoman for Imperial College Healthcare NHS Trust said the patient was being treated at St Mary's Hospital in Paddington, west London.

She said: "We can confirm that we have received one patient from this morning's incident in Westminster. For patient confidentiality reasons we will not provide any further information."

Another person who was being treated at St Thomas' Hospital has since been discharged.

The Metropolitan Police says the incident outside the Houses of Parliament appears to be a "deliberate act".

Assistant Commissioner Neil Basu read a statement saying the unidentified suspect, believed to be in his twenties, was "not co-operating" with police.

An inflated airbag can be seen in the car, which crashed into security barriers, as forensic teams continue their work at the scene.

Image source, Getty Images

Defence minister Tobias Ellwood, who tried to save the life of a stabbed policeman during the 2017 attack outside Parliament, said today's incident was a "stark reminder of the threats we continue to face".

Met Police Assistant Commissioner, Neil Basu, says the police's priority is "to formally identify the suspect and establish his motivations if we can".

The head of UK counter-terrorism policing gave a statement following this morning's incident.

Daniel Sandford
Home Affairs Correspondent

BBC home affairs correspondent Daniel Sandford said it was significant the suspect was "not co-operating" with police.

He said it was "unusual" for a senior officer to say this.

"I think that gives you an idea that this wasn’t a straightforward issue of him being taken to the police station and him saying ‘hang on I’ve made a terrible mistake and I’m really sorry, I fell asleep at the wheel’, this is somebody who is not answering questions, who is not co-operating with police officers," he said.

A rooftop camera has captured the moment a car crashed into a barrier outside Parliament this morning.

(Warning - this video contains scenes some people may find upsetting).

A man can be seen being detained by officers after a car crashed outside the Houses of Parliament.

The man, in his late 20s, was held after the crash and taken to a south London police station.

He is not believed to be known to police.

Armed police, ambulances and firefighters responded to the incident in central London, which happened shortly after 07:30 BST.

Officers were seen surrounding the silver car, which had crashed into a barrier outside Parliament, before a man was arrested.

Image source, PA

Image source, PA