LONDON, May 23 (Xinhua) -- The police confirmed early Tuesday 19 people were killed and 50 more were injured in a blast that occurred outside Manchester Arena right after the end of a concert late Monday night.

A fleet of ambulances raced to the scene in the city center as people fled the scene. People were urged to evacuate the busy Victoria Railway Station close to the arena, with all trains halted. The whole area was also evacuated and a huge cordon set up.

Panic was triggered among the mostly young audience by the blast which took place as they were leaving a concert by the American artist Ariana Grande, said the police.

The Manchester Arena can hold about 18,000 spectators, but it is not clear how many of those struck by the blast had tickets to the concert.

The latest statement by the police said the case is currently treated as a terrorist incident. They said the explosion stuck just before 10:35 p.m. local time.

One concertgoer described to local media how she heard a single bang, and people shouted "It's bomb." That sparked panic, she said, with people, many hysterical, running away from the scene. She said she feared many people, some children, could have been crushed in the stampede for the exit.

"It was just a feeling of panic," she said.

Another eye witness described how many people were crying, with parents desperately clinging onto their children. There was a smell of burning and smoke, said another fan at the concert.

A significant number of casualties were being treated by paramedics, as others were rushed to hospitals in and around the city.

Cabs are taking the concertgoers for free to nearby hotels, and hundreds of people in the city are offering spare beds and rooms for those stranded in the city.

A large area of Manchester city center, just a few hundred meters from the arena, was destroyed in 1996 by a bomb planted by the Irish Republican Army.