India's prime minister said Tuesday there could be no "business as usual" with Pakistan after a deadly flare-up in Kashmir as New Delhi halted a new visa programme and the fallout hit sports events.
While diplomats have warned against allowing four recent cross-border killings to wreck a fragile peace process, Prime Minister Manmohan Singh called the beheading of an Indian soldier on January 8 "unacceptable".
"It cannot be business as usual" with Pakistan, Singh said in his first public reaction to the attack which has caused outrage in the army's ranks.
"What has happened is unacceptable," the premier added on the sidelines of an army function in New Delhi.
"Those responsible for this crime will have to be brought to book."
India says two of its soldiers were killed by the Pakistani army on January 8, one of whom was decapitated and whose head is still missing.
Pakistan denies that its forces were responsible for the killings and says that two of its own soldiers have died as a result of Indian firing.
India's foreign minister reflected a growing sense of frustration in New Delhi on Tuesday at Islamabad's denial of responsibility, saying it only served to destabilise peace efforts.
"Such actions by Pakistani army ... not only constitute a great provocation but leave us to draw appropriate conclusions about Pakistan's seriousness in pursuing normalisation of relations with India," minister Salman Khurshid told a news conference.
"It should not be felt that the brazen denial and the lack of a proper response from the government of Pakistan to our repeated demarches on this incident will be ignored ... or there would be be business as usual."
Indian Kashmir's chief military commander also cranked up pressure on Pakistan, saying a meeting on the border Monday between the two militaries to calm tensions was fruitless.
"We accused them of carrying out the barbaric attack... we insisted that the head be returned," Lieutenant General K. T. Parnaik said in the Kashmir garrison town of Akhnoor.
The deadly exchanges erupted on January 6 along the militarised de facto border in divided Kashmir known as the Line of Control.
After a total break in ties following the 2008 Mumbai attacks, which India blamed on Pakistan-based militants, relations had been slowly improving. Recent talks had focused on opening up trade and offering more lenient visa regimes.
On Tuesday India was meant to begin allowing Pakistanis over the age of 65 to obtain a visa on arrival at the border in Punjab.
However the programme was put on hold until further notice only hours after Indian officials said it had come into force, although the delay was attributed to "technical" reasons.
"Couple of points have to be ironed out on that. There are technical issues, documents required.
We will iron it out after consultation with other agencies," Home Secretary R.K. Singh told reporters.
The visa deal was sealed last month when the interior ministers from both countries met in New Delhi.
Nine Pakistani players were also withdrawn from a new field hockey league in India and asked to return home just before Singh's comments.
"Due to extraordinary circumstances, it has been decided to send the nine Pakistan players home," said Hockey India chief and the league's main organiser Narinder Batra.
Media reports on Tuesday also said the women's cricket World Cup, scheduled to be played in Mumbai from January 31 to February 17, could be affected due to Pakistan's participation.
The Indian Express newspaper quoted sources as saying Pakistan's matches could be moved to Ahmedabad.
The Pakistan Cricket Board said it had written to the International Cricket Council, asking it to ensure the safety of their women's team.
"We have written to the ICC asking it to ensure the Pakistan team get foolproof security after the hockey incident," board spokesman Nadeem Sarwar told AFP in Karachi.
"The PCB has also requested that the organisers could shift the venue for the Pakistan matches within India, if needed."