The explosions were first heard at around 10.45 pm as fans were leaving. Mobile phone footage posted on social media showed scenes of near panic as people were trying to get out of then building.
Nineteen people are believed dead and 50 people are injured after an explosion at the end of the Ariane Grande concert at the Manchester Arena say a spokesman for GMP.
A caller to BBC Manchester said “There were bodies everywhere – I don’t know how we survived.” NW Counter terrorism Unit confirmed they are treating this as a possible terrorist incident
Senior national Counter-Terrorism officers are assembling in London and are liaising with the Home Office. Officers from the North West Counter Terrorism unit are at the scene.
British Transport Police say there was an explosion in the foyer of the arena shortly after 10.30pm as people were leaving.
Inside There was scenes of panic from inside the building at the fans tried to get out .
Andy was in the foyer near the entrance to the arena, waiting for his wife and daughter.
He told BBC 5 live the scene was “like something out of a war film”. He said he was thrown to the ground by the force of the explosion.
“When I get up and look round, there’s just bodies everywhere. I reckon 20-30 bodies. I can’t say if some of them were dead but they looked dead.
“They were covered in blood and were really seriously hurt.
“The first thing I did was I ran into the arena trying to find my family. I couldn’t find them so I pulled back to where everyone was injured to physically look at people to see if it was my family.
“At the same time I started helping the emergency services as best I could while I was trying to get hold of my family.”
He found his family, who were safe, but said there were “kids and teenagers just lying there screaming”.
College student Sebastian Diaz, 19, of Newcastle, echoed other witnesses’ descriptions of mass panic at the end of the concert.
“Ariana Grande had just finished her last song and there was a huge bang. I just saw running and it was just instinct to run,” he said.
“We actually ended up in a corridor and it was a dead end. It was terrifying.
“I found the main doors and people were crying everywhere. Back at the hotel people were crying and on their phones.”
Calvin Welsford, 18, of Bristol: “I was in the front row and it seemed to happen at the very back of the arena.
“It almost sounded like a gunshot. That’s how I would describe it. It was very loud.
“I looked around and people were just spilling down, heading out of the building.
“I was actually having an asthma attack. It was sheer panic. Security told us we needed to leave but they were very caring. People were crying.”
Emergency services responded within minutes and GMP declared it as “serious incident”
A spokesman for the NWAS NHS Trust said:”Due to the incident in Manchester, please only call us for life threatening emergencies at this time. Thank you.”
There was widespread condemnation of the attack on Social media, Facebook and Twitter.