SRINAGAR, India (Reuters) - Militants ambushed an Indian military convoy in Kashmir on Wednesday, killing three personnel, in an escalation of violence that officials have blamed on separatist protests that have tied down security forces for more than a month.

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Indian Kashmir is in the midst of the worst unrest in six years that began early last month when security forces killed a young separatist commander who was idolized by some youth, provoking an outpouring of anger.

Police superintendent Imtiaz Hussain said militants were taking advantage of the unrest to attack security forces after years of declining violence.

Militants ambushed an army convoy early on Wednesday in the town of Baramulla, killing two soldiers, and then struck at a police jeep when it arrived, killing one policeman, he said.”We were aware about the presence of the militants around Baramulla town for over a month but due to violence across Kashmir, they managed to consolidate and carry out an attack,” Hussain said.

At least 64 protesters have been killed and thousands injured during 40 days of unrest, while schools, shops and offices remain closed in much of Kashmir as paramilitary troops patrol.

The turmoil has raised tension with Pakistan which invited India for talks on the disputed territory, drawing an angry rebuke from India.

The nuclear-armed neighbors, which have fought three wars since independence in 1947, both claim the Muslim-majority region in full but rule it in part. U.N. monitors remain on the heavily fortified border between the two sides in Kashmir.

On Wednesday, Indian authorities re-imposed a curfew in the summer capital, Srinagar, to stop a separatist alliance of political and religious groups from holding a sit-in outside the office of the U.N. Military Observer Group to press for its involvement.

“The U.N. cannot watch the massacre in Kashmir as a mute spectator,” said Mirwaiz Umar Farooq, the chairman of a faction of the All Parties Hurriyat Conference.

The U.N. group routinely declines to comment to media, referring queries to U.N. headquarters.

India accuses Muslim Pakistan of supporting Kashmiri fighters while Pakistan accuses India of meddling in Pakistani trouble spots.

India’s Major General J.S. Nain said troops were on alert to stop militants from crossing over from Pakistani Kashmir to foment trouble.

The army says 56 militants managed to cross into Kashmir up to June this year, compared with 36 in 2015. It blames Pakistan’s Inter-Services Intelligence agency for supporting infiltrators.

“The ISI and terrorist organizations want to infiltrate as many terrorists as they can whenever there is turmoil,” Nain said.

Pakistan denies giving material support to Kashmir fighters and denounces rights abuses in Indian Kashmir.