SHOPIAN, HELD KASHMIR - Three Indian soldiers and a woman were killed when gunmen ambushed a patrol in Held Kashmir early on Thursday, part of an upsurge of violence that has hit the restive northern region as it emerges from winter.

An army and police party was returning from a village in the Shopian district of South Kashmir when it came under attack. Six soldiers were wounded in the one-hour firefight, three of whom later died, according to police and witnesses.

"Three army soldiers succumbed to their injuries at the army hospital in Srinagar," said a police spokesman who asked not to be named, referring to the main city in Indian-administered Kashmir.

"Around 2 in the night (2030 GMT), we woke up after hearing firing on the road," said the son of the woman.

"Our mother was sleeping upstairs. The firing stopped after an hour and when we went upstairs, we found our mother dead." The woman was hit by a stray bullet and died, police said.

Area superintendent of police Tahir Saleem said the woman, who lived near the ambush area in south Kashmir's Shopian district, was hit by crossfire.

Television footage showed grieving relatives; a red van with shattered windows and shards of glass on the front seat; pools of blood on the ground and bullet marks on the walls of buildings.

A search was under way for the assailants in the latest in an upsurge of militant violence since Feb. 12 that has killed eight soldiers, eight gunmen and three civilians in Held Kashmir.

India is trying to contain a separatist movement in its northernmost region that is more than a quarter-century old. Protests flared after security forces killed a popular Kashmiri leader called Burhan Wani last July.

The nuclear-armed neighbours have fought two of their three wars since independence over Kashmir, which each claims in full but rules only in part.

Clashes occur frequently in Held Kashmir between rebel groups and the roughly 500,000 Indian troops deployed in the region since 1989.

The groups want independence or a merger with Pakistan for the majority Muslim region, which has been divided between India and Pakistan since the end of British colonial rule in 1947.