Witnesses reported hearing a “huge bang” at the venue during an Ariana Grande gig and police have warned people to stay away from the area.
Greater Manchester Police tweeted: “Police responded to reports of an incident at Manchester Arena. Please stay away from the area.”
Suzy Mitchell, 26, whose flat is opposite the venue, reported hearing a huge bang rocking the neighbourhood.
She told the Press Association: “(I) just heard a huge bang from my bed, came out to the front of my apartments and everyone was running away in big crowds.
“The bang was so big I heard it from my room which is at the back of the apartment blocks.
“Currently lots of emergency services going to and from. But can’t see anything substantial as of yet except fleeing people and lots of cars.”