A Tamil Tiger light aircraft bombed a Sri Lankan air force base next to Colombo international airport before dawn today, killing three airmen and wounding 16.
It was the first such air strike by the Liberation Tigers of Tamil Eelam (LTTE), and the the rebel group said more such attacks by its air wing would follow, threatening to deepen renewed conflict in the island state.
Airline and government officials said the civilian airport, 40 kilometres north of the capital, was not damaged but was closed for several hours following the attack.
The military said the bombs hit a barracks, and that none of its aircraft was damaged.
Sri Lanka's stock market fell 1.4 per cent by early afternoon following the attack.
Nordic truce monitors said the Sri Lankan air force responded with attacks on Tiger terrain in the island's northwestern district of Mannar.
The Tigers, who say they are fighting for an independent state for minority Tamils in the north and east, last attacked the airport in 2001, the year before a ceasefire deal which has since collapsed.
In that attack half of Sri Lankan Airlines' fleet of planes was destroyed. The Tigers have since smuggled an estimated four light aircraft into the country in pieces and reassembled them.