6 February 2012 Last updated at 12:48 ET
A factory has collapsed in the eastern Pakistani city of Lahore, killing at least nine people, including women and children, officials say.
Officials said the blast at the three-storey premises was probably caused by a gas leak.
The building was reported to be illegally manufacturing veterinary medicines.
Authorities rescued at least 11 people, while others trapped managed to escape from the rubble.
The bodies of at least five women and two boys - reportedly aged 12 and 14 - were among those pulled from the debris.
Residents say children below the legal working age of 16 were employed to pack medicines in the 25-year-old factory, in a residential area of the city.
"I was inside the building when the blast happened," said Asad, an eight-year-old labourer.
"Two other boys were with me and they started running. I don't know where they went and if they are alive."
A total of 60 people, including women and under-aged children who worked in the factory, were inside when it collapsed, Rizwan Naseer, head of the state-run rescue service in Punjab province said, the Associated Press news agency reported.
However, the blast happened shortly after opening hours and correspondents say people may have still been arriving.
The building caved in after several gas cylinders inside exploded, the city's deputy commissioner, Ahad Cheema said, AP reported.
Reuters news agency said authorities were having problems transporting heavy machinery to the area to clear the debris because of narrow streets in the residential area where the factory was located.
Rescue workers shifting rubble by hand said they were looking for voids, where people may have been able to survive.
"It's a big disaster. It is too early to say when we'll finish. We want to recover alive as many people as possible," rescuer Ahmed Raza told AFP news agency.