A car crashed into pedestrians and cyclists near the Houses of Parliament in London Tuesday and police arrested a man on suspicion of terrorism, heightening tensions in a city that has seen a string-of vehicle-based terror attacks.

Two people were taken to local hospitals, but authorities said the injuries aren’t believed to be life-threatening.

Armed police swooped into the area after the incident was reported at 7:37am, arresting the car driver and cordoning off streets surrounding the heart of Britain’s government. The nearby Westminster subway station was closed, and police asked people to stay away from the area.

“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.

A man in his late 20s was arrested at the scene on suspicion of terrorist offenses, 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.

Eyewitnesses said the car was traveling 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.

“The car drove at speed into the barriers outside the House of Lords. There was a loud bang from the collision and a bit of smoke,” Ewelina Ochab told The Associated Press. “The driver did not get out. The guards started screaming to people to move away.”

Jason Williams also saw a car moving at high speed.

“It didn’t look like an accident,” he said. “How do you do that by accident?”

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

Less than three months later, a van rammed into pedestrians on London Bridge before three men abandoned the vehicle and attacked weekend revelers in the nearby Borough Market. Eight people were killed and 48 injured in the attack.

On June 19, 2017, a man drove a van into a crowd of worshippers leaving a mosque in north London, killing one man and injuring eight others.