A Chinese takeaway restaurant in Derry was totally destroyed in a gas explosion today, emergency services said.
Police and emergency services are working to remove rubble and debris from the scene on Strand Road, Derry.
Early reports indicate that no one was trapped and a police spokeswoman stressed they had no reports of serious injuries.
A Fire Brigade spokesman said specialist search and rescue teams had been sent to the scene from Belfast.
"The whole building collapsed in the blast at around 9.30 a.m," he said. "We believe the building was clear but we have to work on the assumption that people could be trapped."
People evacuated from shops and houses have been taken to the University of Ulster's Magee campus.
A bar worker on the Strand Road said she heard huge commotion and sirens wailing.
"It looks pretty bad enough, there are a lot of people down there and it looks like a few buildings may have been involved," she said.
Motorists have been advised to avoid the area.