Search and rescue sniffer dogs have been sent into a collapsed building site in Belfast as efforts continue to determine whether any further workers remained trapped under the building.

There are at least six people currently in a serious but stable condition in hospital after the incident this morning when part of a building under construction collapsed in Belfast city centre.

Eyewitnesses said a floor gave way as concrete was being poured onto the top of a six-storey office block being built in Victoria Street.

They said some workers fell about 30ft to the ground and were trapped under the debris when the accident happened on Monday soon after 10.40am.

Nine fire engines and a specialist fire crew, as well as ambulance crews and police officers were initially at the scene.

Victoria Street, May Street and Chichester Street have been closed to traffic, close to the newly opened 'flagship' Victoria Square development.

Part of the building, where a new office block for the Northern Ireland Law Society was being built, also collapsed.

It is believed there may have been up to 60 workmen on the site at the time of the accident.

Some had to be pulled free after the scaffolding, planks and masonry fell on top of them.

It is understood the two most seriously injured workers are Polish and employed by a company from Omagh, Co Tyrone.

Police said their information was that eight people had been rescued and taken to hospital - two seriously injured and the rest with non-life threatening injuries.

(VB/KMcA)(BMcC)