Sri Lankan security forces destroyed four Liberation Tigers of Tamil Eelam bunkers as they continued to lay siege to the crucial Kilinochchi town and 35 Tamil Tigers and six security personnel were killed in fierce clashes in the northern region, the army said on Monday.

Twelve LTTE [Images] rebels were killed in Vannerkulam in the western Kilinochchi battlefront after troops destroyed four of their bunkers on Sunday, the defence ministry said.

As many as eight of the tiger rebels were killed in the area when troops forced into an LTTE bunker line on Sunday.

The other four militants were killed and six others injured in a subsequent gunbattle, it said.

"Two soldiers also laid down their lives in the confrontation," military sources said.

Meanwhile, troops gunned down 11 LTTE rebels in a fierce gunbattle that erupted in the north-east of Akkarayanklulam in Kilinochchi front, the military said.

According to the defence sources, the fighting that commenced on Sunday morning caused heavy damages to the LTTE.

By intercepting LTTE radio communication, the damages inflicted to the rebel side were confirmed, the ministry said.

"Two security forces personnel also made their utmost sacrifice for defending the motherland while engaged with LTTE insurgents," defence sources added.

Meanwhile, troops attacked LTTE bunker in Jaffna and killed four Tamil Tigers in Muhamalai on Sunday afternoon, the Media Centre for National Security said.

After the confrontation, 30 pieces of 7.62 mm ammunition and 148 MPMG ammunition were recovered by troops.

At Nagarkovil in Jaffna, security forces lost two of their personnel due to a LTTE mortar attack, the MCNS said, adding that six soldiers were injured in the attack.

As many as four militants were shot dead during a confrontation in Otiyamalai in Mullaittivu in north-eastern Welioya on Sunday, the MCNS said.

In another incident, one militant was killed and another wounded by troops in Periyakulam area, it said adding that one LTTE cadre was killed in clashes in Andankulam in Welioya on Sunday.

Two militants were fatally shot at Thannimuruppukulam in the region on Sunday.

During subsequent search operations, troops recovered 83 anti-personnel mines and eight IEDs, it said.