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 . Police spokesman Abdullah Afridi said militants fired the rockets along Saryab Road , injuring an additional 15 people . Earlier this month , four civilians were killed and 10 were injured when a bomb exploded near a security patrol in Pakistan 's Balochistan province , police told CNN . Balochistan has long been plagued by sectarian violence between Sunnis and Shias , and separatist Baloch militant groups who demand political autonomy . Quetta , Balochistan 's provincial capital , is widely believed to be a safe haven for senior leaders of the Afghan Taliban , but rarely are militant attacks in Balochistan linked to them .
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 .