Six members of a family, including two children, were killed when a portion of a 70-year-old building in south Mumbai collapsed on Wednesday morning, fire brigade officials said.

A portion of the four-storey 'Sayyed' building located near the busy Crawford Market in south Mumbai collapsed, trapping six residents in the debris, they said.

All the six bodies have been extricated from the rubble, the officials said adding the dead, all members of an extended family, included a woman, a young girl and a boy.

It was a 70-year-old building of Maharashtra Housing Area Development Authority and repairs had been carried out in 1992, MHADA officials said, adding the structure came under its Building Repair and Reconstruction Board.

The building housed three residential and three commercial establishments, they said.

"Piling work next to the building could be the cause of the collapse," BMC Commissioner J Pathak said.

Family members of a victims alleged that the building collapsed due to the vibrations from the repair work being carried out by BMC in a nearby structure.

"Piling should have been done from a distance of 15 ft but the BMC did it from 1.5 metre (5ft approx). Our family members are dead. BMC is responsible for the collapse," a grieving relative alleged.

During the rescue work, a fireman was injured and was given first aid.