At least 38 Tamil Tiger rebels were killed in fierce clashes with the Sri Lankan security forces in the island's troubled northern region, the army said on Thursday.

While 18 rebels were killed on Thursday,  20 LTTE cadre were shot dead yesterday, the defence ministry said, adding that seven soldiers were also injured during the operations.

"Troops manning the Wanni Forward Defence Line (FDL) engaged two groups of LTTE infiltrators, killing at least 14 of them today," the army said.

Giving details, the defence ministry said troops were attacked by a group of LTTE men in Periyathampanai in Wanni this morning, but the security forces managed to thwart the attack successfully.

At least 14 LTTE cadres were killed and 10 others were injured in the incident, it said. During subsequent search operations, troops found seven bodies of LTTE men, along with five T-56 rifles and one multi-purpose machine gun. Six soldiers also suffered injuries in the incident.

Separately, at a location east of Giants Tank in northern Sri Lanka [Images], troops attacked a group of LTTE militants who attempted to infiltrate the FDL.

Five terrorists were either killed or wounded in the incident, the defence ministry said in a statement. However, intercepted radio communications among the LTTE cadres revealed one LTTE cadre was killed and four injured in the incident.

In another incident, at least four rebels were killed today when Navy attacked a cluster of LTTE boats in Mannar in North-west Sri Lanka, a top Navy official said here.

The incident took place when LTTE boats were making way towards Pesalai north from non-liberated Vidattalitivu in Mannar early Thursday morning, the official said. The Navy ships patrolling coastal waters, on detecting strong echoes on radar displays, intervened quickly, Navy spokesperson Commander D K P Dassanayake said.

As a result, LTTE boats were forced to flee leaving a boat with four slain bodies and three survivors, he said. Later, the boat was seized by navy and three survivors were handed over to Mannar Police for further investigations. Extensive search operations were underway to secure the area for safe fishing during later hours, Navy said. One 130 mm artillery shell and a claymore mine were recovered in Pulipanchikal and Pallaththauchanai in Batticaloa district during search operations conducted.

The search operations conducted recently have been immensely successful due to assistance rendered by civilians, security forces said.