An internal wall in the building, which is currently undergoing demolition work, fell to the ground at 11.36am.

Fire crews raced to the scene and scrambled the service's urban search and rescue team amid fears one person was caught up in the collapse.

An eyewitness said: "I was walking past and heard this loud bang.

"Then I saw the workmen running along the scaffolding. One guy came out injured but he didn't seem that bad."

A fire service spokeswoman said: "We have a large number of appliances in attendance after the building collapsed."

The site is being cleared to make way for a huge office development in the heart of Edinburgh's strip bar quarter.

The £20 million scheme involves the demolition of two bars as well as the former Post Office building.