(Updates with rebel denial) By Ranga Sirilal and C. Bryson Hull COLOMBO, Sept 9 (Reuters) - The Sri Lankan military said it had shot down a Tamil Tiger plane for the first time on Tuesday after the rebels launched a pre-dawn air raid and ground assault on a military base which killed at least 25 people. But the rebels denied their plane had been shot down, and said its raid had succeeded in destroying an air force radar station in an assault that killed 20 soldiers. The raid was one of the most audacious counter-attacks by the Liberation Tigers of Tamil Eelam (LTTE) since the army stepped up its advance over the past three weeks, seizing rebel strongholds in what has been the bloodiest fighting since 1999. If confirmed, the downing of the rebel aircraft would provide a boost to the military, frustrated and embarrassed by its inability to impose its air superiority and stop six earlier attacks by the Tigers' ramshackle air force since March 2007. The rebels hit a base in Vavuniya, a rear echelon headquarters located just south of the frontline and 250 km (155 miles) northeast of the capital, Colombo, with an artillery barrage and ground troops before two aircraft dropped bombs. "SLAF (Sri Lankan Air Force) interceptors destroyed one aircraft over Mullaittivu," air force spokesman Wing Commander Janaka Nanayakkara said, referring to a LTTE-held port. Eleven rebels, 12 soldiers, one policeman and one civilian were killed during the fighting, military spokesman Brigadier Udaya Nanayakkara said. Thirteen soldiers, seven air force personnel and nine police were wounded, he said. The air raid was in support of a "Black Tigers" suicide commando unit trying to take out the radar tower, the LTTE said. "The radar station was destroyed in the attack. At least 20 Sri Lankan soldiers were killed," the LTTE statement said. "The aircraft of the Air Tigers that participated in the sortie safely returned home." It said 10 Tiger fighters died. Earlier, the military said the radar station was unharmed. Both sides routinely give widely differing accounts of combat, inflating their wins while downplaying losses. The military restricts battlefield access, so independent confirmation is difficult to obtain. U.N. MOVING OUT Also on Tuesday, the United Nations said it would comply with a government order on Monday ordering all aid workers out of the war zone. The military said it could not guarantee their safety as it pushes to wipe out the LTTE, which is on U.S., U.N., Indian and European terrorism lists. "A precise timetable for the complete withdrawal of all staff is yet to be determined, but relocations will begin this week," the U.N. Sri Lanka country office said in a statement. The International Committee of the Red Cross said in a statement it had provided aid to 84,000 people who have fled the intensified fighting since early July. It said tens of thousands were moving deeper into LTTE-held territory. The military's claim of downing an LTTE aircraft comes as it has ratcheted up pressure on the Tigers on a frontline that stretches coast to coast across the Indian Ocean island nation's north, aiming to encircle the rebel headquarters at Kilinochchi. "At the moment it's only a claim by the air force. We're going to see how they prove it. If they did it, then the air force will have regained their capabilities," said Iqbal Athas, a Colombo-based analyst for Jane's Defence Weekly. The LTTE, fighting to establish a separate homeland for ethnic-minority Tamils in the north and east of Sri Lanka, used its air wing for the first time in March 2007 in a surprise attack on a military airfield in Colombo. Athas said Tuesday's attack signalled that the Tigers were ready to fight back hard: "It's going to become fiercer because the Tigers find the military poised to go into their strongholds. They have begun their offensive phase now". (Editing by Paul Tait)
Soldiers walk to their camps in northern Vavuniya, September 8, 2008. Sri Lanka's advance into Tamil rebels' heartland has unleashed the bloodiest combat in a decade and opened a new phase ...
