The Counter-Terrorism Command of the London Metropolitan Police is leading an investigation into an incident that saw a car collide with barriers outside the Houses of Parliament on Tuesday morning.
Two people were taken to local hospitals, but authorities said the injuries aren’t believed to be life-threatening.
The incident unfolded at about 7:37 a.m. local time.
WATCH: 2 people injured in incident outside U.K. parliament after car crashes into barriers
A man in his late 20s was arrested at the scene on suspicion of terrorist offences, police said. Images from Sky News and social media showed a man in a puffy black jacket who was surrounded by officers before being handcuffed and led away from a silver car.
The incident resulted in the closure of the Westminster Tube station and police remained on the scene to help with the investigation.
WATCH: Car runs into people outside British parliament building in London
“At this stage, we are treating this as a terrorist incident and the (Metropolitan Police) Counter Terrorism Command is now leading the investigation,” the police said in a statement.
WATCH: U.K. police say suspect in car crash outside parliament arrested, treating as terrorist incident
The Guardian reported that streets close to Millbank, Victoria Tower Gardens and Parliament Square were closed off as police attended to the scene.
Witness and businessman Jason Williams described to the Guardian being “shocked” by the scene.
“I was told to move and started to run,” he said.
Eyewitnesses said the car was travelling at high speed when it hit several pedestrians and cyclists, then crashed into barriers outside the Houses of Parliament. Several suggested the incident was deliberate.
WATCH: Police arrest male suspect in UK parliament crash
The incident came over a year after four people were killed and at least 50 were injured after a man drove an SUV into pedestrians on the city’s Westminster Bridge.
The attacker was later identified as Khalid Masood, a British national.
Coverage of the 2017 vehicle attack on the Westminster Bridge on Globalnews.ca
He was killed after being shot by police.
— With files from the Associated Press