Â鶹ӰÊÓ

COLOMBO, Sri Lanka - Tamil Tiger rebels said Saturday the two planes they sent on a daring air attack over Sri Lanka's capital that killed four people, including the two pilots, were on a kamikaze mission and were not shot down.

Meanwhile, a visiting top UN humanitarian official called on the government and the rebels to avoid a "final bloodbath" in the country's civil war saying that many civilians are being killed as the conflict is believed to reach its final phase.

The surprise attack was an embarrassment for the government, which said two weeks ago that it had seized all of the rebels' airstrips, effectively grounding their small force of light aircraft.

Authorities pulled the wreckage of one plane out of a government high-rise office building near air force headquarters in the middle of the city. The second plane crashed near an air force base just outside the international airport north of Colombo.

The rebels said the planes intentionally crashed as part of a suicide attack targeting the two air force installations and characterized the raid as a success, according to the rebel-affiliated TamilNet Web site.

The Web site showed a photo of the two pilots posing with rebel leader Velupillai Prabhakaran, a tradition for those about to carry out suicide attacks. It described them as members of the "Black Air Tigers." The Black Tigers is the name for the rebels' suicide squad.

Air Force spokesman Wing Commander Janaka Nanayakkara confirmed the raid was a suicide mission aimed at the two installations, but said anti-aircraft fire sent the planes out of control and forced them to crash before they reached their targets.

At least one of the planes, the one that crashed near the airforce base, was packed with 130 kilograms of high explosives which did not explode, he said adding that the other aircraft exploded after crashing into the tax office.

The attacks killed four people, including the pilots, and injured 51 others, said Dr. Hector Weerasinghe of Colombo National Hospital.

The raid by the rebels' tiny air wing came amid an all-out army offensive that forced the rebels out of nearly all of their strongholds in the north and left them on the brink of defeat in their quarter-century separatist war.

"It means that the LTTE retains its capacity for surprise unconventional warfare," political analyst Jehan Perera said, referring to the rebels by their formal name, the Liberation Tigers of Tamil Eelam.

However, the apparent shooting down of the planes would be a sign that "the government is militarily on top of the LTTE," he said.

Military spokesman Brig. Udaya Nanayakkara said the failure to bomb any strategic targets was a defeat for the rebels. The Tigers have used a series of successful air attacks in the past to boost their morale and humiliate the government.

"This is the end of the LTTE, that's all I can say," Nanayakkara said.

"We knew they were desperate, we were expecting these kind of suicide attacks...and we were prepared."

But the attack also showed the rebels were not ready to surrender, despite a military offensive that swept them from their de facto capital of Kilinochchi last month and then pushed them into a shrinking sliver of territory along the northeast coast.

The air raid started just after 9:30 p.m. The government immediately shut off all power in the capital, and searchlights crisscrossed the sky. Anti-aircraft fire rippled across the city as tracer rounds flew overhead and flares lit up the night.

The attack was the first air raid in the capital since October, when the rebels bombed a power station on the outskirts of the city.

The rebels were believed to have three or four light aircraft, which they have used sporadically to attack military bases and other facilities but Nanayakkara said he didn't believe the rebel group had anymore aircraft left after the two planes went down Friday.

Meanwhile, John Holmes, the UN's top humanitarian official expressed concerns about the rising civilian deaths in the country's shrinking war zone.

"I fear the reality is that significant numbers of people are still killed and injured everyday in that pocket," Holmes said without identifying the side responsible for the deaths.

Activist group Human Rights Watch on Friday accused both sides of war crimes. It said the military was routinely shelling hospitals, heavily populated areas and government-declared "safe zones." It also accused the rebels of attacking fleeing civilians and forcing those remaining -- including children -- into combat or deadly labour along the front lines.

"What we need to avoid is a final bloodbath, if you like, at the end of this process that could be dreadful for the civilian population as well as for the future," Holmes said.

Sri Lanka's Human Rights Minister Mahinda Samarasinghe said that government's policy is to "ensure the safety of these civilians."

The Tamil Tigers have been fighting since 1983 for an independent state for minority Tamils after decades of marginalization by the Sinhalese majority. More than 70,000 people have been killed.