An explosion brought down a house in the Pakistani city of Karachi on Friday, killing at least five people, but the cause of the blast was not immediately known, a police said.
The blast happened in a poor neighbourhood of the sprawling southern city, Pakistan's commercial hub.
"Five to six people have been killed. The house has collapsed. We are investigating the cause," senior police official Sardar Abdul Majeed Dasti told Reuters.
Karachi has been largely been free of militant violence over the past couple of years but a bomb attack on a religious procession by minority Shi'ite Muslims in the city last week fuelled concern that the militants are expanding their fight to Karachi.