The militants targeted a graveyard in Hazara area, said Muhammad Dawood Junejo, a Quetta police officer.

"Initially, they fired a rocket and then started firing on people in the graveyard," the officer said.

The officer said the incident seems to be an act of sectarian attack.

Quetta is the capital of the Balochistan province, which has had militant attacks in the past.

Last year, about 50 minority Shiites were killed when a suicide bomber struck an Al Quds rally in September.