Article published on the 2008-04-27 Latest update 2008-04-27 14:21 TU
The attack came as police arrested nine suspects linked to a bus bombing that killed 26 passengers outside the Sri Lankan capital on Friday.
Officials say The Liberation Tigers of Tamil Eelam (LTTE) dropped three bombs at two locations, while one soldier was injured in the attacks on what were bases for ground troops.
President Mahinda Rajapaksa said the blast proved they were facing growing pressure on the battlefield in the north.
The attack showed "the terrorists had once again resorted to killing innocent civilians in the face of heavy setbacks on the battlefield", Rajapaksa said in a statement issued Saturday.
Latest defence ministry figures show 3,178 Tigers have been killed by security forces this year. According to official figures, the military lost 230 soldiers in 2008.
The government has stepped up attacks on the Tamil Tigers' de facto state in the north since pulling out of a long-ignored cease-fire in January.
It claims to have killed thousands of guerrilla fighters since then. The rebels deny those casualty figures and have managed to fend off numerous offensives.
In the most ferocious recent clash, scores of troops were killed and more than 100 were wounded along the front lines Wednesday in a battle that was widely considered a disaster for the military.