Colombo, Sri Lanka ? The Sri Lankan navy said today it had sunk 8 Tamil Tiger rebel ships loaded with troops and weapons during a five-hour sea battle, killing around 70 separatists.

It was one of the largest clashes in Sri Lanka’s conflict since weeks of fighting in August left hundreds dead and threatened to shatter a 2002 cease-fire agreement.

The fighting began late Sunday night when the navy spotted 25 rebel ships sailing south.

Navy Cmdr. D. K. P. Dassanayake told The Associated Press “more than 70 cadres are dead” and two other ships, believed to have been transporting arms and ammunition, were burning at sea.

The remaining 14 rebel boats retreated after the hostilities just off the coast of the eastern town of Pulmoddai, he said.

Foreign mediators are struggling to keep alive the four-year old Norwegian-brokered cease-fire which has unraveled amid clashes that have killed at least 1,000 combatants and more than 100 civilians since July.

The Tamil rebels began fighting in 1983 for a separate homeland in the north and east for Sri Lanka’s largest ethnic minority.