Colombo (PTI): Thirty-one Tamil Tigers, including a senior leader of the guerrillas, were killed in heavy fighting with security forces in the embattled northern Sri Lanka, as troops continued their push towards the rebel 'capital' of Kilinochchi, the military said today.

Sri Lankan troops killed 11 Liberation Tiger of Tamil Eelam (LTTE) rebels in separate clashes in Andankulam in north-eastern Welioya area yesterday, it said.

A senior LTTE leader "Lt Col" Neelawannan was killed during a gun battle with security forces in Vennirikulam in the rebel stronghold of Kilinochchi, the government's Media Centre for National Security said.

"LTTE continue to steadily lose manpower as the Sri Lankan security forces advance further into the heart of the LTTE administrative power, Kilinochchi I. This is a major setback for the militants," a Defence Ministry statement said.

Continuing with its operations in Kilinochchi, 330 kilometres north of Colombo, the army gunned down nine LTTE rebels in Venirkulam and Akkarayankulam, it said.

According to sources, the LTTE defence in the south of Kilinochchi includes an earth bund running zigzag from Nachchikudha to Akkarayankulama along with many military trenches and bunkers.

In separate clashes, the troops killed 11 LTTE cadres in Vavuniya, Nagarkovil area in Jaffna and Muhamali, the military said.

At least 30 Sri Lankan soldiers were injured in the fighting with the rebels since Wednesday, the Defence Ministry said.