LONDON (AP) — A helicopter crashed late Friday night into the roof of a popular pub in Glasgow, Scotland, leaving the building littered with debris and emergency crews scrambling to the scene.

Photos of the scene show what appears to be wreckage of the helicopter on the roof with the word “police” across the side. Part of the roof appears to have caved in. Rescue workers swarm the door of the pub.

Local police confirmed that emergency services are dealing “with a major incident”, but would not comment on casualties or if a police helicopter was involved.

There were reports that people may have been trapped inside, but they could not be immediately confirmed.

Scotland’s Fire and Rescue Service said on Twitter it was on the scene of the crash but would not comment further “as very busy”.

Gordon Smart, editor of the Scottish edition of the Sun newspaper, told Sky News he believed it was a police helicopter.

“There was no fireball and I did not hear an explosion,” he said. “It fell like a stone. The engine seemed to be spluttering.”

Labour party spokesman Jim Murphy told the BBC that “it’s a horrible, horrible scene”.

“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 said.

He later told Sky News that 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”.

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