The Liberation Tigers of Tamil Eelam launched a sea-borne attack on army positions at Kilali on the peninsula in the wee hours but were beaten back by dawn, Defence spokesman Upali Rajapakse said.
"We have successfully repulsed the attack and killed at least 50 rebels," he claimed.
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 group's sea tiger leader Soosai led the Tiger offensive, the sources said.
The fresh attacks ended a brief lull in fighting in the peninsula where the Tigers on Friday launched an attack to overrun military positions.
