In a second explosion since Tuesday in Karachi, three people have been killed and at least 15 were injured in a blast on Wednesday. The blast took place in a multi-storey building in the Gulshan-e-Iqbal area of the city, reported Geo TV.
Part of the residential building collapsed after the explosion.
The nature of the blast has yet to be ascertained.
On Tuesday, an explosion hit a bus stop in Karachi; police officials later said that it had been caused by a remotely-detonated bomb. It remains unknown who was behind the Tuesday explosion.
The explosions come amid political turmoil in Pakistan, as thousands are holding rallies against Prime Minister Imran Khan, whom they accuse of being installed by the military in an allegedly rigged 2018 election. The protesters are demanding his resignation.