Sri Lankan officials say Tamil Tiger rebels attacked a government air force base by air and ground early Monday.
Details of fighting at the Anuradhapura base in northern Sri Lanka are still coming in, and there is no word on casualties.
Military officials say a small group of rebels first attacked the base from the ground, then one of the Tamil Tigers' light aircraft flew overhead, and dropped two bombs.
Residents in the area about 200 kilometers north of Colombo reported hearing explosions and artillery fire.
The rebels staged their first aerial assaults on government targets early this year, but no further air raids have been reported for months.
The Tamil Tigers are believed to have smuggled a few single-engine light planes into the country, piece by piece. The aircraft can operate from small airstrips hidden in Sri Lanka's jungles.
Minority ethnic Tamils have been fighting for an independent state in Sri Lanka's north and east since 1983. Nearly 70,000 people have died in violent attacks during that period. Five thousand have been killed since a Norwegian-sponsored cease-fire broke down last year.
Some information for this report was provided by AFP and AP.