We expected [General Musharraf] to rein in these groups which has not been done

Defence Minister George Fernandes

The truce is due to by Republic Day - 26 January - but there has been no word on whether it will be extended.

Defence Minister George Fernandes says an extension would be considered "at the right time" and blamed Pakistan for failing to rein in the militant groups.

Police and special forces have sealed off the main sports stadium in the Kashmiri capital, Srinagar, where the Republic Day celebrations are due to take place.

"Patrolling has been intensified and security has been further beefed up, particularly around Bakshi stadium, its surrounding areas and vital installations," Tirath Acharya, a police spokesman, told the Reuters news agency.

Kashmiri separatists have called for a boycott

The main Kashmiri separatist alliance has called for a boycott of the celebrations.

"We appeal to the people of Jammu and Kashmir to observe a complete shutdown on January 26 and also to observe it as a black day," the All Party Hurriyat [Freedom] Conference said.

In the past, militant groups have often carried out attacks during Republic Day.

Pakistan blamed

In Delhi, the defence minister said an extension to the government's unilateral ceasefire would be considered after analysing the situation.

But George Fernandes said Delhi was concerned at the level of violence and accused Pakistan of backing the militants.

"We expected Pakistan's chief executive [General Pervez Musharraf] to rein in these groups which has not been done so far," he said.

India accuses Pakistan of arming and backing the militants but Islamabad denies the charge, saying it only provides moral and diplomatic support.