Sri Lanka's Tamil Tiger rebels mounted counter-attacks against government troops and killed at least 60 soldiers besieging their political headquarters, the guerrillas said on Sunday.
The Liberation Tigers of Tamil Eelam (LTTE) said they had re-taken positions from government forces who have been closing in on the northern town of Kilinochchi, the Tiger's political capital.
The pro-rebel Tamilnet website quoted Tiger officials saying that they had killed 60 soldiers and wounded another 150 in Saturday's fighting. The rebels also claimed they had captured the bodies of 12 soldiers.
The Tigers did not give details of their own casualties, but the defence ministry said the guerrillas suffered "heavy damages" when troops hit back.
The defence ministry rejected rebel claims of high military losses and placed security force casualties at 13 soldiers killed and 40 wounded.
Both sides are known to make exaggerated claims about the casualties they have inflicted on each other, and independent verification is virtually impossible with journalists and aid workers barred from the conflict area.
The latest Tiger claims of heavy counter-attacks came as the military said the air force had carried out strikes against Tiger positions and government troops had made a fresh bid to penetrate defences around Kilinochchi.
Planes carried out seven bombing sorties on Saturday in support of soldiers trying to capture the town, the defence ministry said.
"Air force fighter jets made seven successive air strikes targeting LTTE defences and strategic locations in Wanni (of which Kilinochchi is the capital)," the ministry said.
The navy on Saturday destroyed a Tamil Tiger vessel carrying arms and other supplies off the island's northeastern coast, the ministry said.
There was no immediate comment from the Tigers about the reported sea battle.
The LTTE said it repelled a multi-pronged offensive by government forces earlier this week, killing 170 soldiers and wounding 420 others on Tuesday and Wednesday. The military rejected these claims.
President Mahinda Rajapaksa's government has been predicting the imminent fall of Kilinochchi for months, and the military recently said it was within "kissing distance" of the town.
In January the Sri Lankan government pulled out of a 2002 Norwegian-brokered truce with the rebels, who have been fighting since 1972 for a state for ethnic minority Tamils separate from the majority Sinhalese community.