Police Special Task Force commandos repulsed an attack against their Pullumalai base on Saturday morning and inflicted heavy losses on the guerrillas, an STF official said.
The bomb, planted on a tree-top, exploded as the crowded bus passed by in the Vavuniya district, 250 km north of Colombo, a police official in the area said over telephone.
The radars were fixed at Seeniappa Darga Casurina jungle near Sundaramudaiyan village in Ramanathapuram district and trials were going on, a senior IAF official told PTI on Wednesday.
The attack came a day after Tamil Tigers carried out their first ever air raid, bombing a military airbase near the international airport here killing three airmen and injuring 16.
It was not immediately clear whether President Chandrika Kumaratunga wanted parliamentary approval of the plan before putting it into place.
Nine Lankan soldiers were also killed.
The navy engaged a flotilla of Tamil Tiger boats off the island's northeast and sank one boat, killing 15 rebels.
156 people have died in the week-long clashes.
The victims were on their way to reinforce government troops battling Tamil Tiger rebels in the same area.
Air Force spokesman, Group Captain Ajantha Silva confirmed that the air force had bombed some targets in the LTTE-held areas in the Eastern province, but refused to divulge what they were.
It was started when the LTTE launched a suicide attack on a ship with Indian crew.
The President is seeking an end to the spurt of violence.
Sri Lanka has asked the Nordic truce monitors not to accede to the rebels' 'unreasonable' demand to remove members in the peace mission who belong to states of European Union, which had outlawed LTTE as a terror organisation.
The new laws will give the security forces and police wide powers of arrest and detention, but stopped short of banning the Tigers as demanded by nationalists.
There was no independent confirmation of the casualties and both sides are known to inflate the losses on the other.
Balasingham, who is living with a transplanted kidney, is already a heart and diabetic patient and has been living in London with his Australian-born wife Adale Anne.
The mediators also praised India's role in the developments in the island nation.
The meeting is being attended by United States, Japan, the European Union and Norway.
Three male and two female police officers, two Catholic priests and a civilian were detained by the Tigers on Friday, after they ventured into rebel-controlled territory in Mannar.
The claim came a day after the Tiger rebels blew up an army bus in Colombo, killing one soldier, and overran a naval base where they claimed 35 sailors died.
The Sea Tigers seized two fast attack crafts of the Sri Lankan navy and dismantled all the armament including a 23 mm canon and an AGL gun before destroying them.
The talks will be the first high-level meeting between the two sides since the peace process stalled in 2003.
Sri Lankan President Chandrika Kumaratunga on Saturday imposed a state of emergency to deal with the aftermath of the assassination of her foreign minister Lakshman Kadirgamar.
"The team is currently in London and we are trying to secure seats with an alternative airline," said Samantha Algama, Sri Lanka Cricket's media spokesman.
An entire platoon of troops and two tanks of the Sri Lankan army were also missing.
The rebel stronghold of Kilinochchi was decorated with red and yellow rebel flags and senior rebels joined parents of the suicide bombers -- known as the Black Tigers -- for a public ceremony.
Naval gunboats intercepted the Tiger boats leading to the battle, which lasted for six hours, it said.
They assured that they will 'not try to topple the government' despite a ruling coalition partner threatening to quit over the issue.
The disclosure came as police reported that five more bullet-riddled bodies were found in the north-central district of Anuradhapura on Tuesday, 3 days after 5 other bodies bearing bullet injuries were found near the capital.
Defence sources said at least six soldiers were feared dead and 60 others wounded in the battle. However, there was no independent confirmation of the army casualties.
The government has urged the LTTE to break the prolonged deadlock and return to the negotiating table.
The Sri Lankan Air Force this evening destroyed an artillery gun position of the Tigers at Pooneryn, just south of the Jaffna peninsula.
Sri Lankan troops and Tamil Tigers have further compounded the fragile ceasefire in the island nation by resorting to heavy artillery fire in the rebel fronts of Jaffna and Trincomalee, which claimed at least four lives.
The blast is supposed to have been triggered by an army unit.