|Electricity to the area was cut following the accident to minimise the risk of fires [Reuters]
Three multi-storey buildings have collapsed in the centre of the Brazilian city of Rio de Janeiro, killing at least three people and leaving debris strewn over a wide area.
Rescue crews continued to search on Thursday for least 16 people still missing a day after the collapse, which left thick layers of debris on cars and motorcycles in the area.
Three bodies were pulled from the rubble of the buildings on Thursday, though local media earlier reported that five people had been killed in the collapse before revising that toll.
"Three buildings collapsed, a 20-storey building, a 10-storey building and a smaller building of three or four floors," Mayor Eduardo Paes told reporters, updating a previous estimate of the damage.
"Giving a total number of victims would be pure speculation," he added.
Hospital officials said five people had been lightly wounded and were at a hospital under observation, adding that the buildings would have been largely deserted at the time of night when the collapse occurred.
Rescue crews pulled four people alive from the debris, Paes announced at the site.
Picking through rubble
Hours after the collapse, rescue crews were still picking through the rubble. There was a strong smell of natural gas in the area, but Paes said that it was unlikely that a gas leak had caused the collapse.
"There apparently was not an explosion. The collapse occurred because of structural damages," he said. "I don't think there was a gas leak."
Witnesses, however, reported hearing a loud explosion-like sound just before the building fell.
"It was like an earthquake. First some pieces of the buildings started to fall down. People started to run. And then it all fell down at once," a witness who identified himself as Gilbert told the Reuters news agency.
City authorities are assessing the risk of collapse of a damaged adjoining building, local news wires reported, without giving the source of the information.
"I ran down the stairs desperate to escape. Just when I left the building it collapsed. I escaped by the skin of my teeth - it's the work of God," Nelson Tomes, 38, an air-conditioning technician, told the iG newswire.
Tomes, who was on the 10th floor of one of the buildings, said he rushed to the stairwell after he heard a "huge noise".
Power supply cut
TV images showed cars covered with concrete and steel rods. Traffic in the area and service in neighbouring subway stations has been suspended, local media reported.
The local electricity distribution company serving Rio de Janeiro also cut power to the area to avert the possibility of fires, given that natural gas could be smelled in the air around the collapse.
Rio de Janeiro is struggling to address concerns over poor infrastructure as it prepares to co-host the football World Cup in 2014, and the Olympic games two years later.
The incident comes months after an explosion apparently caused by a gas leak destroyed a restaurant in the commercial district of Rio, killing three people and igniting concerns over the state of the city's infrastructure.
In recent months, Rio de Janeiro's inhabitants have had to deal with unexpected explosions of sewer lines and landslides in some city slums caused by heavy rain and deforestation.