At least 52 Tamil Tiger rebels and 30 Sri Lankan soldiers were killed in fierce battles in northern Sri Lanka on Sunday, according to both sides.

The Liberation Tigers of Tamil Eelam attacked army defence lines between Mannar and Vavuniya districts since Saturday night inflicting heavy losses, LTTE spokesman Rasiah Ilanthiriyan said.

He said the LTTE destroyed an army artillery launchpad and seized military hardware, including Buffel armoured personnel carriers.

They also released pictures of the captured vehicles and locations.

The LTTE said they killed 30 troops and captured the bodies of 16 of them in heavy fighting.

However, the military said they were back in control of the area that separates the rebel-held territory from the rest of the country along a physical bunker line stretching from Vavuniya to Mannar.

'The army troops successfully repulsed and counter attacked inflicting heavy damages to the Tigers', the defence ministry said in a statement. 'In the retaliatory attack, 52 terrorists were killed and a large numbers were wounded. The terrorists who fled in the face of army retaliatory attacks had abandoned a haul of arms and ammunition'.

Residents in Vavuniya said they heard heavy shelling in the area continuing on Sunday also.

The upsurge in fighting came ahead of a visit to the region by Japan's special peace envoy to Sri Lanka, Yasushi Akashi, who is due to travel to Vavuniya during his four-day visit starting Tuesday.

Akashi was expected to try and revive the island's stalled peace process which has been deadlocked since October 2006.