19 killed, 50 injured in suspected suicide attack at concert; Islamic State supporters celebrate online

19 killed, 50 injured in suspected suicide attack at concert; Islamic State supporters celebrate online

British police said that at least 19 people were killed and 50 others injured in a blast at a music venue in the northern English city of Manchester, and said that they were treating it as a "terrorist incident".

"So far 19 people have been confirmed dead, with around 50 others injured. This is currently being treated as a terrorist incident until police know otherwise," Greater Manchester Police said in a tweet.

Two loud explosions were reportedly heard near the ticket office of the arena.

A video posted on Twitter showed fans, many of them young, screaming and running from the venue. Dozens of parents frantically searched for their children, posting photos and pleading for information on social media. Britain is on its second-highest alert level of "severe" meaning an attack by militants is considered highly likely.

British counter-terrorism police have said they are making on average an arrest every day in connection with suspected terrorism.

"Please stay away from the area. Emergency services responding to serious incident at Manchester Arena. Avoid the area," Greater Manchester Police said in a series of tweets.

Manchester Arena, the largest indoor arena in Europe, opened in 1995 and has a capacity for 21,000 people, according to its website. It is a popular concert and sporting venue.

A spokesman for Ariana Grande's record label said that the singer was "okay". A video posted on Twitter showed fans screaming and running out of the venue.

The UK's Network Rail said train lines out of Manchester Victoria station, which is close to the concert venue, were blocked.

In March, a British-born convert to Islam ploughed a car into pedestrians on London's Westminster Bridge, killing four people before stabbing to death a police officer who was on the grounds of parliament. He was shot dead at the scene.