COLOMBO - The army foiled a last-ditch, predawn attempt by Tamil rebels using boats to breach military defences Sunday, killing at least 70 fighters and destroying a six boats, a military spokesman said.

Brigadier Udaya Nanayakkara said rebels initially posing as civilians had come across a lagoon and made an attempt to breach the defences around 1:30 a.m., but were confronted and killed.

He did not say whether the army suffered any casualties in the incident.

The incident came as the country awaited a formal announcement on the end of the 25-year war against the rebel Liberation Tigers of Tamil Eelam (LTTE).

Sri Lankan President Mahinda Rajapaksa received a warm welcome on his return to the country from Jordan Sunday as crowds outside the Bandaranaike International Airport waved national flags and cheered.

Rajapaksa declared Saturday in Jordan that the Tamil rebels had been finally defeated militarily, but on arrival he made no public statement.

The military has made no comment about the end of fighting with Tamil rebels in the northern part of the Sri Lanka, but the president was due to make a formal announcement in a nationwide address.

Government sources said his address was likely to come after Rajapaksa briefed his cabinet ministers later in the day.

Military sources said as many as 50,000 civilians fled the last rebel-held area during the last three days, and more were emerging from hiding in the area.

The military also reported a series of loud explosions in the last rebel enclaves, but have not given details of the damages caused.

Army sources earlier claimed that senior rebel leaders including top commander leader Velupillai Prbhakaran were trapped in the combat zone, but the government has not confirmed the fate of those leaders.

An estimated 250,000 civilians have fled the rebel zones since January this year and are now in refugee camps in the northern province.

Government troops launched their offensive in August 2006 to recapture rebel held areas in north and eastern parts of Sri Lanka, and gradually cornered them into a narrow land strip on the northern coast.

The fighting in the coastal area was the most difficult part of the operation, as the troops had to move into an area where thousands of civilians were trapped, with the rebels preventing some of the civilians from leaving.