A senior Pakistani government official says a bomb hit a bus carrying Shiite Muslim students in the southern city of Karachi, killing one person.

Roshan Ali Shaikh says Friday's attack also wounded 11 people. Shaikh is the top administrative official in Karachi.

The attack came a day after Taliban gunmen in northern Pakistan forced 20 Shiites off buses, lined them up and killed them.

Pakistan has faced a growing wave of sectarian killings at the hands of Sunni extremists over the past year.

Shaikh says the Shiite university students were on their way to an anti-Israel rally that is held every year at the end of the Muslim holy month of Ramadan.