The Tamil Tigers' homegrown air wing of light aircraft poses a threat to neighbouring India's nuclear installations, Sri Lanka's government said on Monday.
The government has sought to play down the domestic threat of a series of rebel air raids that culminated in an air strike on oil installations near the capital a week ago.
"There is an air threat which has a range of 200-300 nautical miles, and this range brings within it not only cities within Sri Lanka, shipping in the Indian Ocean, but also the nuclear installations of India," Sri Lankan Foreign Secretary Dr. Palitha Kohona told a media briefing.
"And we are talking about a terrorist organisation that did not hesitate to murder the prime minister of our neighbour," he added, referring to the 1991 assassination of Rajiv Gandhi by a suspected Tiger suicide bomber. "So the possibility is always there."
The government is keen for India to become more involved in trying to end the island's two-decade civil war and has played up a regional threat.
Analysts say the Tigers' air wing, a tiny force of an estimated 2-5 small propeller planes adapted to carry bombs, should not be taken lightly and experts are dumbfounded at how the rebels have managed to fly away safely after each sortie.
The rebels have vowed more air raids will follow as a conflict that has killed nearly 70,000 people since 1983 deepens.
There was no immediate comment from the rebels and it was not clear why they would attack south India, home to millions of fellow Tamils.
But there is lingering distrust of the Indian government.
After arming and training Tamil militant groups in the 1980s, New Delhi tried to turn peacemaker and sent thousands of peacekeeping troops across the waters in 1987.
The force found itself dragged directly into the conflict when they tried to disarm the Tigers and about 1,200 Indian troops were killed. The troops withdrew in 1990.