A female Tamil Tiger rebel has blown herself up, killing 28 people and injuring dozens more in the north-east, the Sri Lankan military says.
A military spokesman told the BBC the woman blew herself up as she travelled with civilians fleeing fighting.
He said 20 of those killed in the attack in the Vishwamadu area of Mullaitivu district were soldiers. The rebels have made no comment yet.
Thousands of civilians have fled the fighting over the past few days.
Evacuated
Military spokesman Brig Udaya Nanayakkara told the BBC: "[The civilians] were coming to an area where there were security forces. A woman in that group blew herself up when she was being checked by female soldiers."
Brig Nanayakkara said 20 soldiers, including three women, were killed along with eight civilians. About 50 troops and 40 civilians, mostly women and children, were hurt, he said.
The injured, Brig Nanayakkara said, were being evacuated to hospitals in the area.
The rebels have made no comment but on Sunday the pro-rebel TamilNet web site again accused the army of firing shells into civilian zones, killing 80 and wounding 200.
Independent journalists cannot travel to the war zone so information cannot be verified.
The rebel-held enclave is coming under sustained pressure from the army.
Sri Lankan President Mahinda Rajapaksa has called on the Tamil Tigers to let thousands more civilians leave and then unconditionally surrender.
Aid agencies have expressed grave concern for the more than 200,000 civilians believed trapped.
The government has accused the rebels of preventing non-combatants from leaving and using them as human shields.
But the Tigers say the civilians are staying in the enclave because they fear the army.
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