Scottish officials say there are a number of casualties resulting from the crash of a police helicopter through the roof of a popular pub in Glasgow Friday night, and that some people remain trapped.

But Deputy  Chief Constable Rose Fitzpatrick said it was too early at this stage to provide further details, adding that emergency workers are still trying to rescue people from inside the pub.

"That rescue operation is clearly ongoing. It is too early at this stage to provide any details around why the helicopter came down."

Officials say a number of people have been rescued and taken to hospitals. Asst. Chief Officer Lewis Ramsay said rescuers have made contact with some people still in the pub and are working to stabilize the building.

Injured revellers, who there to see a ska band, fled through a cloud of dust in what witnesses called a scene of horror. Scotland's leader warned that fatalities are likely.

Photos aired on local television showed what appeared to be part of the helicopter's rotors sticking out of the top of the pub's roof. Rescue workers swarmed the door of the pub and several fire trucks were on the scene.

Britain Helicopter Crash

Rescue personnel gather around a popular pub in Glasgow after a police helicopter crashed into the building late Friday. (Jan Hollands via PA/Associated Press)

First Minister Alex Salmond confirmed that a police chopper was involved in the crash, saying that rescue efforts at The Clutha pub in the city's centre were in full swing.

"Scottish resilience operation now mobilized," he said on his official Twitter account. "Given an incident of this scale we must all prepare ourselves for the likelihood of fatalities."

The helicopter had a crew of three — two police officers and a civilian pilot, according to Scottish police. Police said the aircraft was a Eurocopter EC135 T2 and came down around 10:25 p.m. local time. Emergency services responded immediately.

There were reports that people may have been trapped inside, but they could not be immediately confirmed. Glasgow ska band Esperanza were playing when the helicopter began to fall through the ceiling, witnesses said.

"It seems that the band are all OK. Not so sure about everyone else," the band's official Facebook page said.

Witnesses described a chaotic scene as people rushed through a cloud of dust to get out, some with bad gashes to the head and other injuries.

Grace MacLean, who was inside the pub at the time of the crash, said she was "having a nice time" when there was a "whoosh" noise — then smoke.

"The band were laughing and we were all joking that the band had made the roof come down," she told the BBC. "They carried on playing and then it started to come down more and someone started screaming and then the whole pub just filled with dust. You couldn't see anything, you couldn't breathe.

Helicopter 'inside the pub'

People formed a human chain to help pass unconscious people out of the pub so that "inch by inch, we could get the people out," said Labour Party spokesman Jim Murphy, who happened to be in the area when the helicopter came down.

"The helicopter was inside the pub. It's a mess. I could only get a yard or two inside. I helped carry people out," Murphy told Sky News. "I saw a pile of people clambering out of the pub in the dust. No smoke, no fire, just a huge amount of dust."

He called it "a horrible, horrible scene."

Gordon Smart, editor of the Scottish edition of the Sun newspaper, told Sky News that the helicopter "fell like a stone."

"There was no fireball and I did not hear an explosion," he said. "The engine seemed to be spluttering."

Prime Minister David Cameron tweeted: "My thoughts are with everyone affected by the helicopter crash in Glasgow - and the emergency services working tonight."


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With files from Reuters