Police confirmed the explosion in the thickly populated area of Kerbala Gamey Shah in old Lahore was a suicide blast. The toll was likely to rise further, according to sources.

About 90 minutes later a motorcycle bomber detonated in the southern city of Karachi, killing three people, including two policemen, police and hospital officials said.

The Pakistani Taleban claimed responsibility for the Lahore attack which they said was aimed at security officials in revenge for military operations and US drone attacks targeting militants in their northwest stronghold.

Prime Minister Yousaf Raza Gilani strongly condemned the attacks.