London (CNN) A car crashed into security barriers outside the UK's Houses of Parliament during rush hour Tuesday morning, injuring several people in what police are treating as a terrorist incident.

The man's car collided with several cyclists and pedestrians before crashing into the barrier shortly after 7:30 a.m., police said.

The driver, a man in his late 20s, has been arrested on suspicion of terrorist offenses and remains in custody in a south London police station.

Police forensics officers work around a silver Ford Fiesta car that was driven into a barrier at the Houses of Parliament in central London on August 14.

It appears to have been a deliberate act on an iconic London building, and as such, was being treated as a terrorist incident, said Metropolitan Police Assistant Commissioner Neil Basu during a news briefing later Tuesday.

Police were still working on formally identifying the man, who is "not cooperating," said Basu, adding that the driver was not thought to have been known to MI5 or counter-terrorism police.

Read More