NEW DELHI/ISLAMABAD, 25 December — Indian and Pakistani troops exchanged fresh mortar and heavy machinegun fire yesterday as allegations of spying, kidnapping, torture and a dire warning from the chief of the dominant party in the ruling Indian coalition further inflamed passions on both sides of the South Asian divide.

New Delhi expelled a Pakistani diplomat, raising the ante in the posturing and ongoing war of words as Pakistan President Gen. Pervez Musharraf, currently on a visit to China, showed that diplomatic moves were not yet exhausted by pledging to crack down on two militant groups accused of attacking the Indian parliament.

With both the nations on "high alert", the head of India’s extremist BJP party added fresh fuel to the already raging fire by issuing a warning to Pakistan yesterday that it would be "wiped out of the world" if it opted for a nuclear strike against India.

"We will not be the first to use the nuclear weapon," BJP President Jana Krishnamurthy was quoted as saying by the Press Trust of India in an interview with a television channel. "But if it is used against us by Pakistan, its existence itself would be wiped out of the world map," Krishnamurthy said.

Amid the moves and counter moves, Indian Defense Minister George Fernandes arrived in Kashmir yesterday, reviewing military preparedness on the region’s disputed border, while Pakistani Army deployed anti-aircraft guns and moved most troops from the eastern garrison town of Sialkot to the border with India, local sources said yesterday.

Fernandes, who has played down the threat of a full-scale war, refused to speculate on the probability of military action.

The Indian Army yesterday canceled all leave for soldiers stationed along the country’s western border with Pakistan and even asked some of those on holiday to report back to work. "There is no question of issuing any leave to soldiers at a time like this when there is phenomenal troop mobilization on the Pakistani side of our shared border," said a senior army commander who did not want to be named.

"It is true that we have asked some soldiers on holiday to drop everything and rejoin their units in India’s western sector," he added.

Indian forces on the border with Pakistan have been on "high alert" since the Dec. 13 attack on the Indian parliament by five gunmen, whom New Delhi claims were Pakistan-based militants backed by Pakistani military intelligence.

Thousands of tanks and soldiers have massed in the towns of Ganaganagar, Anupnagar and Jaisalmer in India’s western border state of Rajasthan.

Last week, India announced the recall of its ambassador to Pakistan and terminated cross-border rail and bus links, citing Islamabad’s inadequate response to demands that it crack down on the activities of Lashkar-e-Taiba and Jaish-e-Muhammed.

During his visit to China, President Musharraf said his government would take steps against the two groups if evidence proving their complicity was uncovered. Pakistan’s State Bank said yesterday that it had frozen the assets of Lashkar and another Pakistan-based group named by the United States as being involved in terrorism.

"That is not enough, much more needs to be done," Indian Foreign Ministry spokeswoman Nirupama Rao said. "Instead of focusing on tackling the terrorist groups on their soil as we have asked, (Pakistan) is diverting attention to other issues."

Indian police, meanwhile, said they had arrested a parliament official for allegedly passing "sensitive" information to a Pakistan High Commission (embassy) staffer. A police statement said Ajay Kumar, a senior executive assistant in parliament’s administrative staff, was caught giving information on defense, atomic energy and ship design to the staffer, Muhammad Sharif Khan.

India ordered Khan’s expulsion yesterday.

The statement said Kumar’s interrogation revealed that Khan had several times asked him about security arrangements around Parliament House and to arrange a security pass for him to watch legislative proceedings.

Categorically rejecting these charges, Pakistan’s Foreign Office statement said, "These absurd Indian allegations represented yet another desperate attempt to implicate Pakistan," in the Dec. 13 terrorist attack on the Indian Parliament.

Pakistan accused India of kidnapping and torturing Khan and said it had lodged an official protest with Indian authorities. "During interrogation, (Khan) he was stripped naked, severely beaten and tortured, resulting in visible and internal injuries," the Pakistan Foreign Ministry said.

Indian Foreign Minister Jaswant Singh firmly denied yesterday any custodial maltreatment. "We deny it completely," Singh told reporters.

Local sources in Muzzaffarabad said Pakistani Army has deployed anti-aircraft guns and moved most troops from the eastern garrison town of Sialkot to the border with India.

Kashmir’s Revenue and Relief Minister Abdul Qayoom said hundreds of panic-stricken people had begun migrating from border areas following the exchange of fire which killed three border guards over the weekend.

Indian Border Security Force (BSF) officials said India had also stepped up security on its eastern border with Bangladesh to prevent Pakistan sending militants through the porous frontier.

With tensions rising between the nuclear-capable powers, Prime Minister Atal Behari Vajpayee said at the weekend that India was ready for any eventuality.

"Peace is India's ideal goal and we pursue it zealously. But if crisis knocks on our door the country will not shy from its duty," Vajpayee said.

"The world should know that although we pray for peace we are well-versed in the art of war."