Tensions have risen in recent weeks after anti-India rebel groups opened fire on civilians.
An Indian army spokesman says suspected insurgents have shot dead five soldiers in Indian-administered Kashmir in the deadliest incident since February.
“Perhaps a JCO (junior commissioned officer) and four soldiers were killed during the search operation by an intruder. The operation is ongoing,” Colonel Devendra Anand said on Monday.
The shooting took place near a hilly pass near the Line of Control (LoC), which divides the disputed Himalayan region between India and Pakistan.
It was the deadliest attack on troops in the area since a ceasefire was declared between India and Pakistan on the de facto border in February.
The Kashmir region is claimed by both India and Pakistan, who have managed parts of it since their independence in 1947.
For more than three decades, insurgent groups have been fighting Indian troops, demanding either the independence of Kashmir or the unification of Muslim-majority Pakistan.
Thousands of civilians, soldiers and rebels died in the war. India has accused Pakistan of aiding the insurgency, but Islamabad has denied the allegations.
The region has been under sanctions since August 2011, when tensions escalated after New Delhi revoked the semi-autonomy of Kashmir, enforced new laws and abolished others.
The tendency to kill
Tensions have risen again in recent weeks, with the shooting of civilians, including two teachers, last week – an attack by an anti-India rebel group.
Seven civilians were shot dead in six days last week, including two teachers in Kashmir on Thursday, sparking outrage in Kashmir and across the country. Politicians from all over have condemned the killings.
A senior senior police official told AFP on condition of anonymity on Sunday that about 500 residents had been detained across the disputed area on suspicion of involvement with banned religious and rebel groups.
“No stone will be left unturned to find the killers,” the official added.
New Delhi sent a top official of the anti-terrorism intelligence department to investigate the area.
Authorities say at least two civilians, including activists from India-ruled political parties, have been shot dead in Indian-administered Kashmir so far this year.
Twenty-two of them were Muslims, officials added.
The two teachers shot dead by gunmen at a government-run school were from the Muslim-majority region’s Sikh and Hindu communities.
A relatively new rebel group, The Resistance Front, has claimed responsibility and accused the occupiers of working for the occupiers and the occupiers.
The statement, issued in English only, was circulated in several WhatsApp groups and could not be independently verified by Al Jazeera.
The killings have caused panic among minorities in India-administered Kashmir, with local media reporting that many are fleeing the region.
On Saturday, Human Rights Watch called on the accused criminals as well as Indian security forces to be held accountable for their actions, including those accused of abuse, including harassment, torture and extrajudicial killings.
Meenakshi Ganguly, HRW’s director for South Asia, said in a statement that “Kashmiris are being subjected to incessant violence amid militant attacks and insults by government authorities and security forces.”