Having pushed back the Tamil Tigers to a small stretch of northern coastline, Sri Lankan troops today captured the last sea tiger base in Chalai and are now closing in on the top commanders of the Liberation Tigers of Tamil Eelam.

Army tanks and infantry moved deep into the sea Tiger base in Chalai region in Northern Mullaittivu after killing four top LTTE [Images] leaders, including Vinayagam, number three in the hierarchy list of sea tigers.

"Our troops have just moved into Chalai. The capture would limit the sea tiger operations," Military Spokesman Udaya Nanayakkara told PTI.

With the area under their control fast slipping, the top LTTE commanders, according to army sources, have no option but to dig in for a battle or escape.

That Sri Lankan troops have almost reached the top brass of the LTTE, the sources said, is indicated by the fact that for the past few days security forces are having increasing encounters with the elite Black Tigers, which are supposed to be the most battle hardy and loyal suicidal squad of LTTE chief V Prabhakaran.

"Deputy LTTE sea tiger leader and three other sea tiger leaders were killed in a fierce confrontation took place in north of Chalai on Wednesday," the army sources said.

Vinayagam was killed as troops on mission to capture Chalai launched an effective offensive thrust against LTTE rebels, the defence sources said.

During interception of LTTE communication channels, it was revealed that Tamil Tigers were unable to locate the body of Vinayagam so far, as troops continued their offensive on remaining LTTE positions in the area.

Meanwhile, in-charge of LTTE land fighting group Kader and sea tiger Pooneryn area leader Pahalawan were also killed in the clashes, the defence ministry said.

Sea tiger special leader known as Sinna Kannan was killed in north of Chalai on Wednesday, the ministry said.

He was later given the self-styled rank of 'Lt. Colonel', Electronic Warfare sources said after intercepting LTTE communication channels.

Eight more sea tigers were also killed during the battle, the ministry said.

Meanwhile, Sri Lanka [Images] air force Kfir jets carried out two air raids on a LTTE communication centre, 1.5 kms north east of Puthukudirippu junction in Mullaittivu and another on an LTTE command centre used by senior tiger leaders nearby, the air force said.

The pilots of the fighter jets confirmed the accuracy of engaged targets, it said.

The sea tigers had acquired a formidable sea going capability and had sunk number of Sri Lankan naval boats and even foreign Merchant vessels operating in water close to the coastline they controlled.

With the fall of Chalai, the Tigers are now left with just 20 km of coastline in Mullaittuvu. The Defence Ministry said the Tigers had used suicide bombers to prevent capture of Chalai, but these were foiled.

Meanwhile, air force MI-24 Fighter Helicopters and fighter jets carried out 13 air strikes on LTTE points in south and south-east of Pudukudirippu.

The air strikes were launched to support the advancing troops who are conducting operations in the area.

Separately, clashes took place between the troops and the LTTE militants in Weerakulam in Mullaittuvu on Wednesday, the Media Centre for National Security (MCNS) said.

Troops sustained minor damages in the clashes, it said, adding the rebels sustained severe damages during clashes in Kuruvikulam in Mullaittivu South West on Wednesday.