A sea battle launched by Tamil Tiger rebels in northern Sri Lanka has left about 50 insurgents and 17 sailors dead or missing, in a sharp escalation of violence that shoved the country back onto brink of civil war today.

Sri Lanka’s military said it sank five Tamil Tiger rebel boats today in retaliation for the sinking of a navy vessel which European ceasefire monitors said may have taken the nation a step closer to civil war.

Eight Sri Lankan sailors missing after their vessel was destroyed in an explosion blamed on Tamil Tiger rebels are presumed dead, the navy said today.

The Tamil Tiger rebels accused the Sri Lankan navy today of barring Tamil fishermen from going to the sea, a day after suspected insurgents rammed a fishing boat packed with explosives into a navy vessel, killing 13 sailors.

The Sri Lankan government today asked parliament to extend an emergency rule decree imposed after the assassination of the country’s foreign minister by suspected Tamil rebels, as European peace monitors held talks with guerrilla leaders.

Norwegian envoys who are trying to help broker Sri Lanka’s peace with its Tamil Tiger rebels headed for the island nation today while its president and prime minister remained locked in a power struggle that has thrown uncertainty on the peace process.