Tamil Tiger rebels in Sri Lanka have detonated a roadside bomb in the north of the country, killing at least 10 soldiers, the military say.
The bomb went off as a bus carrying off-duty soldiers was travelling in a convoy through the town of Chettikulam in Vavuniya district.
Earlier in the same area officials blamed the Tamil Tigers for killing at least four local guards.
The rebels are fighting for a separate homeland in the north and east.
Nearly 70,000 people have died since the conflict began in 1983.
Officials say that the convoy was carrying soldiers going home on leave. It was travelling from the north-western town of Mannar when the blast occurred.
"A claymore [mine] exploded targeting a bus carrying troops from Mannar to Vavuniya," a spokesman at the Media Centre for National Security told the Associated Press news agency.
"It was definitely the Tigers."
There has so far been no comment from the rebels on either attack.
Fighting between the army and rebels has recently intensified
Unlike most mines, claymores are placed above the ground rather than underneath, and can be detonated remotely at a given moment for maximum impact.
They fire steel shrapnel as far as 250m in a fan shape in front of where they have been placed.
Correspondents say that Mannar and Vavuniya districts have been the scene of recent fierce clashes between government forces and the Tamil Tigers.
The latest attack came as security was stepped up in the capital, Colombo, amid fears of bomb attacks by the separatist rebels amid an upsurge of fighting.
While the army has captured large tracts of rebel territory in the east, the Tigers still control a large section of the island's far north.
A ceasefire signed between the two sides in 2002 is still in place on paper, but has broken down on the ground.
Much of the recent fighting until now has taken place in the east.
The rebels have said if government forces try to advance on their areas in the north, they will resist using every means at their disposal.
The Tigers say minority Tamils are discriminated against by the majority Sinhalese population.