Colombo, Apr. 23 : The Sri Lankan Army on Thursday said that it is closing in on LTTE Chief V. Prabhakaran''s hide out, adding that the guerrillas now controlled a mere 10-12 square kilometres of territory on the northeast coast, where thousands of civilians are still trapped by the fighting.

The army claim as Seevaratnam Puleedevan, secretary-general of the Liberation Tigers of Tamil Eelam (LTTE) peace secretariat, urged the international community to intervene by forcing a permanent ceasefire, which Sri Lanka has ruled out.

The military says around 50,000 people have fled the Tiger-held area so far since Monday, and had given the LTTE until noon Tuesday, a deadline already passed, to surrender or be destroyed.

A senior United Nations official urged Sri Lanka''s Tamil Tiger rebels to lay down their arms and let the UN help trapped civilians to leave the conflict zone.

Claude Heller, Mexico''s ambassador at the UN in New York, spoke to media after chairing an informal meeting of the UN Security Council on the issue.

Though the 15-strong Council passed no resolution on the conflict, Heller said he was voicing members'' concerns.

The United States expressed disappointment with the Sri Lankan Government over the current humanitarian crisis.

On Wednesday, India voiced its unhappiness over the continued killing of innocent Tamils in Sri Lanka and asked the LTTE to stop its "barbaric" attempt to hold civilians hostage, as Prime Minister reviewed the situation in the island nation.

The Prime Minister, Dr. Manmohan Singh, convened a special meeting to review the situation arising outof the crisis in Sri Lanka. It was attended by External Affairs Minister Pranab Mukherjee, Defense Minister A. K. Antony, Foreign Secretary Shiv Shankar Menon and National Security Advisor M. K. Narayanan.

Mukherjee later stated that authorities in Colombo had a responsibility to protect Sri Lankan citizens and asked the LTTE to stop the barbarism of holding civilians as human shields. He also added that he had "no sympathy for terrorists but every sympathy for civilians.

Sri Lanka President Mahinda Rajapaksa, however, ruled out any chances of pardoning Prabhakaran if he was captured alive by advancing government soldiers.

On Wednesday, the LTTE''s media co-ordinator, Daya Master, and another key rebel leader George surrendered before the army. (ANI)