Sections of top Tamil Tiger leadership on Wednesday began to surrender before rapidly advancing Sri Lankan forces, signalling an imminent collapse of the Liberation Tigers of Tamil Eelam after a two-decade long relentless battle.

Two top Tamil Tiger leaders, including its former spokesman Daya Master and George, aide of slain political head Tamilchelvan, surrendered to Sri Lankan forces at Putumathalan, Defence Ministry spokesman Keheliya Rambukwella said.

The government "strongly believes" that Tamil Tiger supremo Vellupillai Prabhakaran and his other top aides were still in the area and had not escaped, Rambukwella said, claiming that the Liberation Tigers of Tamil Eelam "had lost all its military capabilities."

"They are fighting on their last legs and it is a losing battle. The only way for them to stop this military operation is to lay down arms," he said, as troops pushed deeper into the No-Fire Zone, the last patch of the 18 sq km land held by the Tigers as thousands of trapped Tamils civilians continued to flee the northern war zone.

The surrendered leaders indicated that there were only 10,000-15,000 people left in the 'no-fire' zone, he said. "This is a very clear sign that LTTE [Images] has accepted defeat and this is a start of a new era," a spokesman said.

Over 95,000 civilians have so far crossed over to government controlled 'safe zone' till this morning, a Defence Ministry spokesman said.

The United Nations and other aid agencies estimates are that there could be anywhere up to 2,00,000 people trapped in the No Fire Zone. The spokesman claimed that Lankan forces had captured 8 sq kms of the 18 sq km area of the 'no-fire zone' where the Tigers have been hemmed in after being ousted from almost all their strongholds.

In fresh fighting, troops claimed to have already killed 46 Tiger cadres and seized a large quantity of arms and ammunition. Pro-LTTE website Tamilnet made no mention of surrenders or fighting trends. It merely said that in government forces shelling a Church had been damaged at Valaignarmadam, in which many people who had taken shelter there, were killed.

The rapid Sri Lankan advance came as the first-ever satellite imagery of the embattled zone showed that tens of thousands of Tamil civilians were squeezed into the last small strip of land controlled by the Tamil Tigers. The imagery released by the US State Department shows about 25,000 tents packed into a coastal strip about 18 sq km, promoting US and Red Cross officials to ask Colombo for a pause to enable women and children escape the conflict zone.

After capturing Putumathalan on Tuesday, which triggered off the civilian exodus, Sri Lankan troops on Wednesday moved deeper into the No Fire Zone, capturing Vishwamadukulam and Alankulam and in search operation, came across 22 dead bodies of LTTE cadres.