A white van has reportedly plowed into at least 20 pedestrians on London Bridge, and while police have arrived on the scene to shut down traffic, no announcement has been made regarding whether the incident is a terrorist attack.

Witnesses told BBC that officers quickly arrived on the scene after a van veered off the road and started driving on the sidewalk and plowing into people.

The Daily Mail reported that the van hit 20 pedestrians. The BBC is reporting that the van hit five or six people.

Metropolitan Police confirmed via Twitter that a serious incident took place on London Bridge, but have otherwise held onto other details to avoid spreading rumors.