Sri Lankan Air Force jets on Thursday attacked a key Liberation Tigers of Tamil Eelam base in rebel-held Mulaithivu even as the army killed 15 Tamil guerrillas in ground clashes a day after a fierce sea battle between the two sides left 40 Tigers dead.

"Sri Lankan Air Force supersonic Mig-27 and KFir combat fighters made dashing sorties at Vellamullavaikkal, north of Mulaithivu on Thursday morning," the defence ministry said.

Quoting Air Force sources, it said fighter pilots hit the target, successfully destroying the LTTE facility during the precision aerial sorties. The aerial raid was launched following ground surveillance and real time air reconnaissance information, the ministry said in a statement.

It said according to reliable intelligence, the LTTE was conducting a special training session at the facility, which was continuously functioning since 2001. The target, located northwards along the coast of Mulaithivu, was kept under constant reconnaissance.

The LTTE has been conducting multi-pronged war exercises at the facility when it was hit by the jets, it said. "The LTTE's Kilinochchi leadership is yet to reveal losses," the army said citing intercepted communication.

In ground battles, the army said, advancing troops destroyed six LTTE bunkers, killing at least 15 Tigers south of Adampan in north-western Mannar. It said around 20 LTTE rebels had sustained injuries in the attack.

The fighting came after the defence ministry said at least 40 Tamil Tigers were killed in an intense sea battle in the northern Jaffna coast on Wednesday with the Navy destroying six LTTE boats. The rebels claimed the Navy has also suffered casualties in the confrontation.

Also on Thursday, a Special Task Force official was killed and another injured in a claymore mine explosion that took place when the STF team was conducting a search operation in eastern Batticaloa.

Meanwhile, the Pro-LTTE website Tamilnet claimed three Sri Lankan Army soldiers were killed and many wounded on Thursday when the LTTE repulsed an attack in the Muhamalai Forward Defence Lines in northern Jaffna.

Quoting LTTE officials, the website said arrangements were underway to hand over the bodies of the SLA soliders to the International Red Cross Committee. It said there were no LTTE casualties in the Muhamalai clash.