An investigation has begun into the cause of a fire at a skyscraper being built in Dubai, after at least two people died and dozens were injured.
Labourers awaited rescue at the top of the Jumeirah Lake Towers
Trapped labourers tried to climb down the outside of the building and at least one fell to his death from near the top of the 37-storey building.
Many of the workers were reportedly immigrants from South Asia and China.
Human rights groups have repeatedly criticised working conditions for foreigners in Dubai's building boom.
About 300 workers were on the site of the Jumeirah Lake Towers when the fire broke out at around 1230 (0730 GMT) on Thursday.
Eye-witnesses saw up to 50 workers perched precariously on the upper storeys of the building, awaiting rescue, as thick, acrid smoke poured from the middle and upper floors of the skyscraper.
Some tried to lower themselves down, clinging to the outside of the building, much of which had already been shelled in glass.
"One guy in red was trying to climb down and then he just fell. It was horrible," Louise Olson, who lives opposite the tower, told the Associated Press news agency.
"The two dead were of Asian nationality... 57 labourers working in the 37-storey building were injured" an official told Dubai's WAM state news agency.
Other unconfirmed reports said four people had died.
"Fire started in the electricity and sewage pipes in the upper floors starting from the 31st," WAM quoted the unnamed official as saying, without mentioning what was thought to have caused it.
The tower, which was nearing completion, is one of hundreds currently under construction in the city.
Another is the Burj Dubai - or Dubai Tower - which is due to be the tallest in the world when it is complete, and which reached its 100th storey this week.
Hundreds of thousands of workers from Asia are facilitating the fast pace of development in the city, says the BBC's Julia Wheeler in Dubai.
New laws have recently been introduced to improve their situation and counter criticism that they are being exploited and poorly looked after.
The skyscraper fire will prompt discussions as to the need for emergency facilities and hospitals to be built in the rapidly developing areas of the city, where a largely expatriate population lives, our correspondent says.
It will also bring into question the ability of rescuers to deal with incidents in high-rise buildings.