The pro-rebel Puthinam.com said Prabhakaran was due to deliver his speech later Thursday, marking the end of a week of ceremonies commemorating some 22,000 Tamil fighters who perished in his campaign for a separate state.

The last 18 months have been disastrous for his Liberation Tigers of Tamil Eelam (LTTE), who want to carve out an ethnic homeland in the north and east of the Sinhalese-majority island. 

Heavy fighting raged on the outskirts of Kilinochchi on Thursday despite monsoon rains, military officials said, adding that troops were poised to breach new barricades built by the rebels. 

On Wednesday, the government said the fall of Kilinochchi was imminent.

Former Tamil rebel-turned politician Dharmalingam Sithadthan said Prabhakaran may vow to hit back and try to lift the morale of his depleted force. 

"I believe he still has the capacity to carry out headline grabbing attacks, but that will not be enough to change the current military balance of power," Sithadthan said. 

The Sri Lankan government pulled out of a Norwegian-brokered truce in January and stepped up military pressure on the Tigers. President Mahinda Rajapakse says he will accept nothing less from the LTTE than their surrender. 

Analysts say Prabhakaran has been left with little room for manoeuvre. 

Military officials said thousands of troops were also stepping up an offensive against the north-eastern town of Mullaittivu, the last population centre still under firm rebel control. 

Reports of casualties had been sketchy and the defence ministry has stopped issuing daily reports on the losses suffered by both sides. The Tigers too have been irregular in disclosing details of fighting. 

Authorities in Sri Lanka have restricted access to the embattled areas for journalists as well as most aid workers, meaning that claims by either side in the decades-old conflict are normally impossible to verify. 

The rebels were ejected from the east in July 2007 and lost their political chief in a government air raid, while much of their fleet of ships used to smuggle black market weapons into the country has been reported sunk. 

Prabhakaran in his last year's Heroes' Week speech vowed to hit back against what he called the "genocidal" government, but instead saw the military unleash its biggest ever offensive against his forces in the island's north. 

Tens of thousands have died in the drawn out separatist campaign since the formation of the LTTE in 1972. Political attempts to end the conflict have led to more bloodshed.

Courtesy: Yahoo