Government forces shot dead at least 33 Tamil Tiger rebels and wounded many more in a fresh outbreak of fighting in northeastern Sri Lanka on Thursday, the military said.

Tamil Tiger rebels mounted an assault against troops in the coastal Chalai area, but security forces repulsed the attack and recovered a large haul of weapons, military spokesperson Brigadier Udaya Nanayakkara said.

"We recovered 33 bodies of the terrorists and 33 automatic assault rifles and several other weapons and ammunition," Nanayakkara said, adding that security forces were consolidating their positions in the area.

Tiger rebels have been cornered in a narrow strip of land in the coastal district of Mullaittivu.

The military has said it hopes to defeat the Tigers completely by April, to end a 37-year conflict.