At least 17 people have lost their lives in Indian Kashmir in some of the fiercest fightings this year in the restive Himalayan region, police said on Sunday as authorities braced for more violence.

A total of three Indian soldiers and 13 suspected militants died in several clashes south of Srinagar, the main city of the region.

Besides, four civilians were also killed and dozens injured when police opened fire on thousands of demonstrators who poured onto the streets, throwing stones and chanting slogans against the Indian rule.

There were also demonstrations in Srinagar, where authorities ordered all schools shut on Monday as rebel groups called for protests.

Seven of the alleged militants were killed along with two soldiers in a protracted shootout in the village of Dragad, where helicopters were seen swooping low over the battle zone.

Another man, described by Indian authorities as a militant, was gunned down in a brief exchange of fire in Dialgam.

Pakistan condemns India's brutal actions

Foreign Office on Sunday condemned "the use of brutal and indiscriminate force by India that resulted in the loss of lives of Kashmiri youth".

"This mindless killing spree exposes, yet again, the ugly, inhuman face of the state-terrorism that India has been perpetrating against the Kashmiris for decades," read a statement issued by the Foreign Office.

"We have repeatedly pointed out that the Kashmiri youth is being deliberately and systematically targeted with a view to breaking the will of the Kashmiri people. However, such cowardly actions of the occupying forces only serve to fortify the resolve of the Kashmiri people," the FO spokesperson was quoted as saying.

It further stressed that "no amount of Indian propaganda to paint the legitimate and indigenous Kashmiri struggle as terrorism could succeed in misleading the world."

Kashmiris have been fighting for decades for independence or for a merger with Pakistan. Last year was the deadliest of this decade in the region, with more than 200 alleged militants killed in a counter-insurgency offensive dubbed “Operation All Out”.

That upsurge in violence has escalated in 2018, with 51 alleged militants already killed this year.

The weekend clashes were the worst since a three-day skirmish in the forests of northern Kashmir last month left ten dead ─ five unidentified militants and five government forces, according to officials.