Three police officers have been killed in a suspected Tamil Tiger ambush in northern Sri Lanka.
It is understood the rebel group attacked a police water tanker with a claymore fragmentation mine near the northern town of Vavuniya.
More than 100 people have been killed in recent days in the worst violence since a 2002 ceasefire halted two decades of war.
Some 700 people have died so far this year, almost all of them since early April, as land and sea rebel attacks become more frequent.
A suspected Tamil Tiger mine attack on a civilian bus in central Sri Lanka on Thursday killed 64 people, prompting the heaviest government air strikes on rebel areas since the truce.
The rebels threatened retaliation if air strikes continued and yesterday a Tamil Tiger naval and ground attack in the northwest left more than 40 dead or missing.
International condemnation of the bombing of bus passengers prompted calls for both the Tigers and the Sri Lankan government to return to the negotiating table.
If the violence continues, it is feared attacks could come to the capital Colombo, sending investors fleeing from a $20 billion economy.
At least 64,000 people have been killed in Sri Lanka since the outbreak of hostilities in 1972.
