Greater Manchester Police confirmed that 19 people were killed in an explosion on Monday evening at the Manchester Arena where US singer Ariana Grande was performing.

Greater Manchester Police said in a statement that the explosion occurred around 10:35 pm. Police are treating the incident, which injured more than 50 people, as a possible terrorist attack until they know otherwise.

This footage shows concertgoers outside Manchester’s Victoria Station near the site of the explosion. The station was evacuated and trains to and from the station were suspended, according to Network Rail.