Man held after 'terror attack' near Houses of Parliament in London

A man in his twenties has been arrested in London on suspicion of terrorism offenses after a car crashed outside the Houses of Parliament in Westminster on Tuesday morning, in what police are describing as a terrorist incident.

At 7:37 am, a vehicle plowed into a number of cyclists and pedestrians before crashing into barriers outside Parliament.

Police were seen surrounding the car and armed officers arrested a man at the scene. They have reported that no one else was in the car and "no weapons have been recovered at this stage". The Metropolitan Police's Counter Terrorism Command is investigating the incident.

Westminster underground station remains closed and streets around Parliament, including Millbank and Parliament Square, have been cordoned off, and the London Ambulance Service said it had taken two people to hospital with non-life-threatening injuries.

The man was later discharged, while the woman remained in hospital, Metropolitan Police Assistant Commissioner Neil Basu told a news conference.

The BBC reported eyewitnesses saying that the silver car appeared to deliberately hit members of the public.

"The car had struck a barrier on a lane used for access to the parliament building with force," witness Jason Williams told Reuters. "It's a very serious incident. There was smoke coming from the vehicle."

Images shot by a Euronews journalist showed police pointing their guns at a vehicle. Footage on social media showed a handcuffed man being led away by heavily armed police. Other footage showed a cyclist lying on the street.

The area was the site of a terror attack in March 2017 when Khalid Masood plowed a car into crowds on Westminster Bridge, killing four people. Masood abandoned his car then stabbed and killed a police officer before being shot in a courtyard outside Parliament.

Parliament is in summer recess and most lawmakers were not in the building and Prime Minister Theresa May is on holiday abroad.

On Twitter, she wrote: "My thoughts are with those injured in the incident in Westminster and my thanks to the emergency services for their immediate and courageous response."

Mayor of London Sadiq Khan said he was in close contact with London's Metropolitan Police, who added that the "public can also expect to see extra police officers－both armed and unarmed－out on the streets in and around central London".

The Houses of Parliament are surrounded with security barriers of steel and concrete, measures which were extended after the attack in March 2017.

AP and AFP contributed to this story.