Six Sri Lankan soldiers have been killed and two are missing after Tamil Tiger rebels attacked an army outpost in the south-east, the military says.
The war has intensified in recent months
There were no reports of rebel casualties in the incident.
Most of the recent fighting has been in the north where the rebels still control a swathe of territory.
In the north, the military said at least 20 rebels had been killed in a series of clashes, the fiercest of which were near Vavuniya.
The rebels have not commented on the government's accounts of the fighting and there was no independent confirmation of the casualty figures.
Fighting has been intensifying between the Tigers, who want an independent state for the Tamil minority, and the government.
Our correspondent says attacks on the south-east coast such as Tuesday's battle near the Yala wildlife sanctuary are unusual.
Military spokesman Brigadier Udaya Nanayakkara said an army outpost manned by nine soldiers had been overrun by Tamil Tiger rebels.
Brig Nanayakkara said six were killed and one was wounded. Two more are missing.
Hours later, an army tractor sent to collect the casualties hit a landmine and another soldier was killed and three more were wounded.
Meanwhile, there was heavy fighting in the north too.
The military said it had killed 24 rebels in battles around the frontlines near Vavuniya that divide rebel- and government-held areas. One soldier was also killed.
Troops had recovered the bodies of seven rebels after battles in the district, a military spokesman said.
In a separate incident, two policemen manning a checkpoint were shot dead.