India said it is expelling Pakistan's ambassador in the latest sign of deepening tensions between the two nuclear countries, following an attack on an army camp and a bus in Indian-administered Kashmir earlier this week that killed more than 30 people. Pakistan expressed disappointment over the decision, and said it would continue efforts to reduce regional tensions. Indian and Pakistani troops exchanged heavy fire along the border for a second day.

Foreign Minister Jaswant Singh announced the diplomatic measure against Islamabad after a meeting of the Cabinet Committee on Security in New Delhi - the highest body that considers national security.

India recalled its top envoy from Islamabad in December, after an attack on the Indian parliament, but Islamabad's high commissioner to India had stayed on. Mr. Singh said that will change.

"A direction has been issued by the CCS [Cabinet Committee of Security] to the Ministry of External Affairs to require of Pakistan, for the sake of parity of representation between the two countries, the High Commissioner of Pakistan that is currently in India be required to return to Islamabad," Mr. Singh said.

The security meeting was called after India said Pakistan was "directly responsible" for Tuesday's attack in Kashmir, and promised "appropriate action." Pakistan has condemned the attack and denied any involvement in it.

At the meeting, Indian Prime Minister Atal Behari Vajpayee consulted with the heads of India's three military services as well as Cabinet members to review security in Kashmir. New Delhi blames Pakistan for the infiltration of separatist militants into Kashmir, which Islamabad denies.

Indian authorities say there has been heavy mortar firing across the tense Kashmir border between Indian and Pakistani troops for the second straight day. Foreign Minister Singh blamed Pakistan for starting the firing.

"There was a provocation from Pakistan side, and in retaliation very heavy damage has been caused on the Pakistan side in Jammu and Kashmir," the Indian foreign minister said.

New Delhi's latest diplomatic move comes as the two nuclear-armed rivals remain locked in a tense military standoff. Since last December, both countries have massed tens-of-thousands of troops along their common borders. Fears about a possible war between the two countries have increased, after the latest attack on the army camp in Kashmir.