Islamabad , Pakistan ( CNN ) -- Three civilians and a police officer were killed Wednesday after militants fired two rockets at security checkpoints in Pakistan 's western city of Quetta . an additional 15 civilians and a police officer were killed Earlier this month in a rocket attack . Police say the attack injured 3 people . Balochistan is Quetta 's provincial capital .
an additional 15 civilians and a police officer were killed Earlier this month in a rocket attack . Police say the attack injured 3 people . Balochistan is Quetta 's provincial capital .