COLOMBO, Jan 2 The Sri Lankan army captured the Tamil Tigers' northern stronghold of Kilinochchi on Friday, inflicting a hammer blow to the LTTE's struggle for a Tamil homeland.

But within an hour of the presidential address, a suspected suicide attacker blew himself up near the headquarters of the Sri Lankan air force in Colombo, killing three airmen and injuring 37, 12 airmen included.

Military officials recalled that the Tigers had a history of retaliating with attacks in the capital to ease pressure on the northern front.

President Mahinda Rajapakse announced the fall of the Tiger 'capital' in an address to the nation, vowing to annihilate the guerillas after dislodging them from Mullaittivu, their last base located on the northeastern tip of the country.

The president, in “one final message” to the LTTE, asked it to surrender but significantly, extended no invitation to talks.

Kilinochchi, in the Northern Province, has long been the linchpin of the Tamil struggle for an independent homeland, which has claimed more than 70,000 lives in a bloody civil war since 1983.

Tamilnet.com, a pro-LTTE website, scorned the president's statement, claiming that the Tigers had moved their headquarters further northeast before the town fell.

“The Sri Lankan army has entered a virtual ghost town,” the website said. “The Tigers, who have put up heavy resistance so far, kept their casualties as low as possible in the defensive fighting.”

Colombo and the hill station of Kandy burst into euphoria after Mr Rajapakse's announcement, with ecstatic crowds lighting bonfires and exploding crackers.

“A short while ago, our brave and heroic troops have fully captured Kilinochchi, which was considered the main bastion of the LTTE. Our troops have completely taken over the fortress of the LTTE, which has been described by our own leaders and accepted internationally as the most powerful terrorist organisation in the world,” Mr Rajapakse said in his speech.

Agencies add Lt-Gen Sarath Fonseka, the army chief, vowed to go after the last remaining military base of the Tigers.

“It won't take a year to finish them off, to eliminate them,” Gen Fonseka said, adding that taking Kilinochchi was the culmination of a major offensive that began in March 2007.

Analysts said the capture of Kilinochchi could make the capital and far south more vulnerable.