By Roland Buerk
BBC News, Colombo
Whatever you may think of their goals and methods, Sri Lanka's Tamil Tigers have always been innovative.
Experts say the technology was rudimentary but effective
It was they who refined the suicide bomber, and used them to devastating effect.
And what other insurgent groups can boast a naval wing? The rebels have boats armed with guns, known as the Sea Tigers.
Now they have confirmed what Sri Lanka's government had suspected for a long time - they have an air capability too.
The first mission of what the rebels are calling the Tamil Eelam Air Force, or TAF, took place overnight.
Two light aircraft - according to the government it might have been one - set off, presumably from a jungle airstrip in the north of the country, and flew south.
If they were detected they were not stopped.
Their target was the air force base at Katanayake, north of the capital.
They flew overhead and dropped several bombs, killing three airmen on the ground and wounding many more.
They also terrified passengers waiting for flights at the nearby international airport, some of whom described panic and chaos as people ran for cover amid the sound of explosions.
As the air base echoed with the sound of machine gun fire the light aircraft turned around and flew back home.
The rebels have released photographs of the plane they said was responsible.
Pilots are shown wearing pale blue Tiger striped uniforms, in one shot grouped around the elusive rebel leader Vellupillai Prabhakaran.
There is no shot showing the entire aircraft, but the Sri Lankan Government believe it to be a Czech-designed Zlin-143. One picture shows four bombs mounted underneath the fuselage.
"It's a very basic system they seem to have put on their aircraft, very hit and miss," said one foreign defence expert based in Colombo.
"It's interesting though, a bold effort. To fly down at night and get back is quite a message to send. It's very Biggles."
The government says its air defence system was a success because the fighter jets housed in hangars at the air base were not damaged.
And there was nothing like the scale of damage caused in 2001, when a Tiger attack on the airport complex left half the national airline fleet in flames.
Vellupillai Prabhakaran was pictured with the Tamil "air force"
But the Sri Lanka Air Force has launched an investigation into how the planes got through.
And the police have also launched an inquiry.
A spokesman, citing the ongoing investigation, refused to confirm reports they were looking into the possibility that Special Task Force police commandos had spotted the rebel aircraft flying in the north of the country up to an hour before they struck.
Analysts believe the attack has opened a new dimension in Sri Lanka's decades-long civil war.
"It changes the conflict completely," said Iqbal Athas of Jane's Defence Weekly.
"For two decades the fight has been confined to the land and the sea. Now we see the emergence of the air capability of the Tigers. It's the first time they've demonstrated the capability that they can not only use it, but get away."
And he pointed out that army camps, the homes of important figures, and naval craft at sea have suddenly become more vulnerable.
'More to come'
The Tigers said this would not be the last aerial attack.
"It is not only pre-emptive, it is a measure to protect Tamil civilians from the genocidal aerial bombardments by Sri Lankan armed forces," rebel military spokesman Rasiah Ilanthirayan told Reuters.
The military said it prevented the attack from being worse
"More attacks of the same nature will follow."
The air raid comes as the Tigers were seen to be facing setbacks on the ground.
In recent months they have been driven from many towns and villages along the coast in the Eastern province.
And one senior government figure has talked of defeating the rebels militarily within two to three years.
The government has long suspected that the rebels were trying to get aircraft, smuggling them in pieces to be assembled in their northern stronghold.
"It's not a new dimension," said military spokesman Brigadier Prasad Samarasinghe.
"They were constructing a runway about two or three years back. During the ceasefire agreement they have brought all these things. This is the first time they have come and they were successful in putting the bombs.
"But they were not successful as per the plan that they wanted as they couldn't destroy any air force facilities. Definitely this is not a major threat and it will be neutralised."