Tamil Tiger rebels opened fire on an army post in northwestern Sri Lanka on Wednesday, killing one soldier and wounding another, military officials said.
The rebel Liberation Tigers of Tamil Eelam (LTTE) attacked soldiers in Mannar district under the cover of darkness and troops retaliated, officials said.
Separately, security forces have shot dead at least 10 Tiger rebels in various confrontations in the island's restive northern regions since Tuesday morning, they said.
The latest deaths raise the number of rebels killed by security forces since January to 4,290, according to the defence ministry, which says 388 security personnel and police have died in combat over the same period.
The official figures cannot be independently verified since journalists are barred from visiting front-line areas.
The government insists it has the upper hand in the decades-long conflict with the Tigers, and has poured a record 1.5 billion dollars into the war effort this year.
The Tigers have been fighting for a separate homeland for the Tamil minority since 1972. Tens of thousands have died in the conflict.