At least two persons were killed and over a dozen others injured in a bomb blast at Abul Hassan Ispahani Road in Karachi on Sunday evening, police say.
The blast occurred near the main entrance of Imambargah Mustafa in Abbas Town.
The death toll, it is feared, may go up as seven of those injured in the blast are in critical condition.
The injured have been shifted to Patel and other hospitals. Two victims have been identified as Azhar Hasan, 38 and 25-year-old Muhammad Haider.
Heavy firing erupted in Abbas Town while supply of electricity was also suspended in the area.
According to SSP CID Chaudry Aslam, explosive material was attached with a motorcycle which was blown up with a remote-controlled device.
Five shops were also damaged in the powerful blast.
Shia scholar Allama Abbas Kumeli condemned the blast and termed it a serious security lapse.
In a statement, President Asif Ali Zardari denounced the motorcycle blast and condoled with families of the victims.