An unruly mob pelted stones at security forces in Drugmulla in Kupwara district after the Friday prayers. Unable to disperse the crowds, security forces opened fire, killing one of the demonstrators.
In south Kashmir's Kulgam district, a mob attacked the Yaripora police station with a barrage of stones.
Suddenly, a militant hiding in the mob first hurled a grenade and then fired from an AK-47 rifle at the policemen.
"One policeman was killed in the firing and six others were injured," a senior police officer told IANS in Srinagar.
In Nathnusa village in north Kashmir's Kupwara district, guerrillas hurled a grenade at CRPF troopers, injuring four of them.
No major incident of violence took place on Friday in Srinagar where there was heavy deployment of security personnel to thwart post Friday prayer protests.
Authorities had announced curfew in all the 10 districts of the Kashmir Valley on Friday to prevent mass protests.
More than 35 people have been killed and hundreds injured in street clashes between protesters and security forces since the July 8 kiling of a top militant, Burhan Wani.