Sopore town, 50 kilometres north of Kashmir's summer capital Srinagar,
has been under indefinite curfew since Friday after two young men died when troops opened fire in response to anti-India protesters who attacked their vehicle.
Police clamped the curfew on the town after thousands of people poured into the streets, torched a security vehicle and attacked a police station to protest against the killing of the two men.
On Saturday, thousands of demonstrators, defying the curfew, staged noisy protests and clashed with security forces.
Chanting We want freedom! and Blood for blood!, hundreds of residents again defied the curfew on Sunday, prompting security forces to fire rubber bullets that killed a 24-year old man, a police officer said.
A rubber bullet pierced his neck. He died on the way to Srinagar's main hospital, the officer said, adding several others were injured.
Residents said the victim was not part of the protest and was heading to a mosque when he was hit.
Tensions have risen in recent months in Indian-administered Kashmir, where two decades of rebellion against New Delhi's rule have left thousands dead.
In all six civilians have been killed in incidents implicating Indian security forces over the past two weeks.
Nuclear-armed rivals India and Pakistan each rule part of Kashmir but lay claim to all of the scenic Himalayan region.
Authorities ordered a judicial probe into the earlier killing of the two young men by security forces in a bid to stem protests. -AFP