KARACHI -- Three people including a college principal were shot dead on the street in this southern Pakistani city Monday in what police called a terrorist attack.

Syed Zafar Mahdi, 50, the Principal of Jamia Millia Technical College, was killed along with two companions when three assailants on a motorcycle opened fire as he arrived at work, a police official said.

"Apparently it is an act of terrorism and we cannot take it as a sectarian killing," Karachi police chief Asad Jehangir told AFP.

Mahdi was from the minority Shiite community in Pakistan, and his murder bore all the signs of a sectarian assassination by militant extremists from the majority Sunni sect of Islam.

Karachi has seen growing numbers of professionals, mainly doctors, targeted for attack since the start of the year despite government pledges to stamp out sectarian bloodshed.