An unexploded shell went off belatedly at an encounter site killing several civilians on a bloody Sunday in Jammu and Kashmir that witnessed the deaths of 15 people: seven civilians, five militants and three soldiers.

Shortly before the killings, governor Satya Pal Malik had told reporters that there had been a “huge improvement” in the situation.

Young people, including teenagers, had swarmed into a house in Larnoo village, Kulgam — after the forces had killed three Jaish militants holed up there and left — to help the family salvage its belongings from the debris.

It was then the shell went off. It wasn’t clear whether the forces had fired it or whether it had been part of the militants’ arsenal. The standard operating procedure requires the forces to clear encounter sites of explosives before leaving.

A police spokesman said the people had entered the house “in spite of a request not to, as a thorough search was on for explosives”. But the absence of casualties among the forces in the blast raises a cloud on the claim that they were still searching the rubble.

Officials said a few civilians died in the explosion and the rest in firing by the forces when mobs clashed with them in the streets, protesting the blast deaths.

State police chief Dilbagh Singh, however, said all seven civilians died in the blast, which would make it the highest civilian toll at an encounter site. Several injured are critical in hospital.

Elsewhere, three soldiers and two militants died as the forces battled heavily armed infiltrators in the Sunderbani sector of the Line of Control in Rajouri, Jammu.

The Kulgam deaths led to more clashes and prompted the imposition of curfew in parts of south Kashmir. The separatist Joint Resistance Leadership has called for a shutdown and more protests on Monday.