Militants dressed in Indian army uniforms killed at least eight people in attacks on an Indian police station and army camp near the Pakistan border on Thursday, triggering calls to cancel talks between the rival nations' leaders.
Just a day before the attack, Indian Prime Minister Manmohan Singh announced that he would meet his Pakistan counterpart, Nawaz Sharif, on the sidelines of the U.N. General Assembly on the weekend.
The leaders of the nuclear-armed neighbours are expected to discuss rising violence in the Kashmir region.
Hours after the initial assault early on Thursday, a Reuters witness heard several explosions and shooting at the army camp, where the militants were thought to be holed up in a building.
Helicopters hovered overhead and security forces surrounded the camp, near the town of Samba in India's Jammu and Kashmir state.
The group of three or four gunmen first attacked the police station, about 10 km (6 miles) from the border with Pakistan, killing six, then hijacked a truck, security forces said.
"They abandoned the truck on the national highway and perhaps took another vehicle and carried out an attack on the army camp in Samba," said Rajesh Kumar, an inspector general of police.
The gunmen killed at least two soldiers, including a lieutenant colonel, a senior army officer told Reuters. Some wounded men were seen being carried away by colleagues.
India's state-run television news channel quoted interior minister Sushilkumar Shinde as saying the militants had entered from Pakistan.
Pakistan's army and government were not immediately available for comment.
India and Pakistan have fought two of their three wars since independence in 1947 over Muslim-majority Kashmir, which they both claim in full but rule in part.
India has accused Pakistan of supporting militants fighting security forces in Indian Kashmir since 1989.
Militant strikes in India's Kashmir, as well as shooting and mortar fire between Indian and Pakistani forces across the border, have risen this year after a decade of falling violence.
Some Indian officials fear that a new wave of Pakistan-based militants from Islamist groups such as the Lashkar-e-Taiba will turn to India as Western troops leave Afghanistan next year.
In a separate incident, the Indian army said on Thursday it had killed at least a dozen militants from a group of 30 it said had crossed over from Pakistan in northern Kashmir. Lieutenant General Gurmeet Singh said that operation was still going on.
Immediately after the attack in Samba, politicians from India's nationalist opposition party called for the cancellation of the weekend talks. They will be the first between the two leaders since Sharif was re-elected in May following an election campaign in which he called for better ties with India.
While Prime Minister Singh strongly condemned what he called a "heinous terrorist attack" he suggested the meeting With Sharif, expected on Sunday, would go ahead.
"This is one more in a series of provocations and barbaric actions by the enemies of peace," Singh said in a statement. "Such attacks will not deter us and will not succeed in derailing our efforts to find a resolution to all problems through a process of dialogue."
Yashwant Sinha, a leader of the Hindu nationalist Bharatiya Janata Party, the main opposition party, said there was no point talking to Pakistan if it was unable to prevent such attacks on India.
"We are not going to achieve anything and therefore I have no hesitation in saying that the prime minister should call off the talks ... I insist he should call off the talks even at this stage." he said.
Pakistan denies arming or training militants, but says it offers moral support to the Muslim people of Kashmir who it says face rights abuses by Indian forces.
According to the South Asia Terrorism Portal, which tracks violence in Kashmir, 128 people, including 44 security personnel, have been killed in the region this year, before the latest attack. That compares with 117 people killed in 2012.