Ten people were wounded in the suicide attack against the Chenkaladi army camp, a military official said, as the defence ministry reported other violence, which left a soldier and three rebels dead.

The suicide bombing by the driver and his assistant came a day after the Tigers flew single-engined planes over the main military air base adjacent to Sri Lanka's only international airport and dropped bombs, killing three airmen and wounding 16 others.

Two separate teams are investigating the air strike -- an embarrassing blow to the country's defence establishment -- and President Mahinda Rajapakse also held an emergency meeting with political party leaders here on Monday night.

"The air power of a frenzied and desperate organisation as the LTTE is a grave threat aimed not only to Sri Lanka but also to the entire South Asian region," the president's office said in a joint statement.

It said political parties in Sri Lanka urged the international community to "make a proper assessment of this very real danger."

The Tigers said the military carried out retaliatory air strikes inside rebel-held territory on Monday afternoon, but there were no casualties.

Tuesday's suicide bombing was in the coastal district of Batticaloa where government forces have been conducting intensive operations against the Liberation Tigers of Tamil Eelam (LTTE) since December.

The office of the Eelam People's Democratic Party (EPDP), a pro-government Tamil party, which cooperates with security forces, was also destroyed.

"Two soldiers and four EPDP men were killed and about 10 wounded at the camp," a military official in Batticaloa told AFP. "There are two other bodies to be identified."

Military sources said the Tigers had tried to stage a similar suicide bombing against Chenkaladi last week, but failed when the explosives went off prematurely.

Chenkaladi was attacked last week together with three other military camps in Batticaloa district, leaving four soldiers dead and 30 wounded, according to the military.

There was no immediate word from the Tigers about the latest attack. The defence ministry separately said three rebels were shot dead in the country's north while the Tigers killed a government soldier in a clash in Batticaloa.

Relief workers have raised fresh concerns for the safety of civilians in Batticaloa as more people fled their homes and sought the safety of public buildings to avoid getting caught in the crossfire between troops and rebels.

At least 150,000 people have been internally displaced within the district, where troops and Tamil Tiger rebels have been trading long-range attacks for weeks.

Security forces have vowed to flush out the Tigers from the restive eastern region after the military captured the key Tiger bastion of Vakarai in January after several weeks of intense battles.

Troops have also tried to capture a jungle base known as Thoppigala from the Tigers, who are fighting for an independent homeland for the island's ethnic Tamil minority.

More than 60,000 people have been killed in Sri Lanka's Tamil separatist campaign since 1972. The two sides agreed to a truce in February 2002, but subsequent peace talks have broken down.