At least 22 Tamil Tigers and a soldier were killed in separate clashes in restive northern Sri Lanka [Images] as government troops captured a key base of the Liberation Tigers of Tamil Eelam hours after taking control of two defence lines in the region, the army said on Sunday.

As many as three rebels were killed and three soldiers injured in a confrontation at Mullikulam in Mannar on Sunday morning, the defence ministry said.

"During Saturday's military advance into non-liberated territory ahead of Wanni defences, security forces overran what was identified to be the LTTE's 'Vietnam base' located at general area of Periyapunichankulama," the ministry said.

Troops on Saturday also moved 1 km into the entry-exit pass at Uiylankulam in Mannar-Vavuniya border, forcing the LTTE rebels to retreat with their arms and ammunitions, it said.

Ten LTTE bunkers were destroyed during the battle while eight rebels were killed and 14 injured, the military said, adding, a soldier also lost his life while six others sustained injuries.

In Vavuniya, rebels vacated their defence line at Thampane on Saturday afternoon while clashes intensified near the defence line in Mannar, it said.

At Nagarkovil defence line in Jaffna, troops engaged in heavy mortar and artillery barrages on Sunday morning, destroying four LTTE bunkers and killing at least eight rebels, the army said.

Sri Lankan security forces launched an attack on Saturday at LTTE positions ahead of Kilali forward defences in Jaffna, killing two militants, it said. Two under construction bunkers of LTTE were also destroyed on Saturday evening, the sources added.

Meanwhile, according to troops manning defences at Kokkuthuduvai in Welioya in North-eastern Sri Lanka, one militant was killed on Saturday while attempting to breach the Forward Defence Lines. Troops also defused 101 anti-personnel mines during an operation at Periyathampanai South and Umayarattuvarankulam in Vavuniya, the army said.