Pakistani officials say a bomb attack in the city of Quetta has killed 11 people and wounded dozens more.

Quetta senior police officer Zubair Mehmood told reporters the explosion in a crowded area of the city also injured 27 people. It was not immediately clear what kind of a device it was. Reports said the explosion may have targeted paramilitary soldiers.

Quetta is the capital of Baluchistan province, which has grappled with a decades-long separatist insurgency. It is also home to Islamic militants.

Earlier, Pakistan officials said U.S. drone-fired missiles hit a house in the northwest tribal region, killing at least five militants.

The Pakistani government has long publicly condemned the drone strikes as a violation of its sovereignty, but the attacks are believed to be carried out with help from Pakistan's intelligence agency.