At least 13 people, most of them women, were killed when a building in the southern Pakistani city of Karachi collapsed Saturday, injuring at least another eight, police said.

The incident took place in Karachi's densely populated Khajoor Bazaar when all the floors of a five-storey building collapsed, trapping dozens of people in the debris.

"We have recovered 13 dead bodies, eight people are injured," police official Irfan Meao told AFP by telephone, adding that eight women and two children were among the dead.

A representative of the local government said that they were investigating the collapse.

"We are investigating the reasons, the building may be damaged because of last month's heavy monsoon rain water," Dilawar Khan told AFP, adding that rescue work was still under way.

He said that there could be at least one more body trapped in the debris.

Last month Karachi's first torrential rains of the monsoon season killed at least 26 people, mostly women and children, and injured hundreds.