LONDON — British police responded to eyewitness reports late Saturday that a van plowed into pedestrians on London Bridge. There were also reports of an incident in Borough Market. It was not clear if they are related.

On London Bridge, witnesses described seeing a white van mounting the sidewalk and injuring at least six people. A BBC reporter who was on the bridge at the time said the van was driving around 50 miles per hour. It was driven by a man.

Metropolitan Police confirmed an incident but released few details.

"We are dealing with an incident on #LondonBridge, when we have more information we will update this twitter feed," they tweeted at 10:30 pm local time.

Twitter users began uploading footage of police on the scene.

There were reports of gunfire near Borough Market, an area that houses many food stalls not far from London Bridge. Police said armed officers had been sent to the scene but again provided few details.

Reports of the incident reflected fear that the incident could be terrorism. Britain has weathered two recent terrorism attacks in recent months. In March, four people were killed in London after Khalid Masood rammed his car into pedestrians on Westminster Bridge, before fatally stabbing a policeman outside the Houses of Parliament.

On May 22, a British-born suicide bomber killed 22 people and injured 59 others at Ariana Grande's concert in Manchester, England.