ABC News Online
Up to 200 workers are believed trapped in the rubble of an eight-storey factory which has collapsed in Bangladesh.
Officials say six people have been confirmed killed.
The concrete building, packed with night shift workers, caved in soon after midnight (local time) on Monday when a boiler exploded.
An eight-storey factory has collapsed in Bangladesh. (Reuters)
Firefighters are using shovels and their bare hands to dig frantically as survivors call for help from beneath the debris.
Distraught relatives have assembled at the scene.
One man has called police on his mobile telephone to say he is trapped with 20 other people.
Survivors working at the garment factory, 30 kilometres north-west of Dhaka, say the building collapsed after they heard a loud explosion.
"Within two or three minutes, the whole building started to shake violently," Mahubur Rahman, who was working on the fourth floor with around 90 other people, said.
"The next thing I remember is waking up under some machinery with about six or seven other people. The fire brigade rescued me but four of my fingers are crushed and I have chest injuries," he said.
Another survivor, Helaluddin, says he is a supervisor on the sixth floor where about 80 or 90 people are working.
"I was walking towards the stairs. Suddenly there was this noise and then I felt as if someone had pushed me. Moments later I found myself in complete darkness," he said.
Major General Aminul Karim of the Bangladesh Army says six bodies have been recovered.
Saber Sharif, commander of the Rapid Action Battalion security force, says seventy-seven people, most with crush injuries, have also been rescued.
"From the information we have gathered we estimate there are about 200 still inside," he said.
Firefighters say trapped workers have been calling out to rescuers.
"We are hearing noises from the rubble. One man called out he was dying and needed help. But it's difficult to reach people because the building has collapsed in layers and inside there are very few pockets," firefighter Parimal Chandra said.
"For the people there, chances of survival are getting thinner all the time if we cannot bring in some specialist equipment. Without that, it could take more than two weeks to lift all the debris," he said.
Police officer Nurul Islam says rescuers are still trying to find the man who called for help on his mobile phone.
"A knitwear worker telephoned us at 8:00am (local time) to say that he was trapped with 20 other people in a space," he said.
"Unfortunately we were unable to call back because the line was not working and we have not been able to find those people yet," he said.
A crowd of several thousand, including weeping relatives, have gathered at the scene.
"My brother Abdul Razzaq is a knitting machine operator. He was working there," said one woman named Selina.
"Normally there is no one working there after 10:00pm but they were working night shifts because they had a big order."
Another woman, Jharna, says there would have been about 200 people inside the building.
"My husband Nurul Alam is missing. I am just waiting here for news. I was working there myself last night but I left at 10:00pm to go home," she said.