The incident occurred at Shadab market in Hashtnagri area of Peshawar city where the victims associated with cosmetic business were ambushed, SP City Mustafa Tanvir told PTI.
Unknown gunmen opened indiscriminate fire killing one Sikh Jagmot Singh and injuring Param Singh and Manmit Singh - resident of Mohallah Jogan Shah Dabgari bazar in the city, he said, adding the victims are believed to to be relatives.
Police have registered a case and started investigation.
Angry members of the Sikh community blocked the main G T Road as a protest against the attack. There are also reports of some skirmishes after the attack.