(KUNA) -- As many as five sailors and 16 Tamil rebels were killed in a sea battle between the navy and Tamil rebels off the northwestern coast of Sri Lanka Wednesday. The Sri Lankan navy spotted rebel boats heading towards a naval base at Kalpitiya, 160 km north of capital Colombo, and engaged the boats in a confrontation Wednesday during which 16 Tamil rebels had been killed, news agency Indo-Asian News Service reported. Five of the seven sailors who went missing following the incident have been killed. Another three sailors were injured while one of the patrol craft was damaged. The rebels from the Liberation Tigers of Tamil Eelam (LTTE) had claimed that a naval vessel had sunk.On Thursday, Norwegian mediators are scheduled to discuss issues related to an official ceasefire in the north and east of Sri Lanka following a demand by the rebels that all monitors from European Union countries withdraw by September 1, 2006, the agency reported. Norwegian-brokered peace process to resolve the 25-year-old ethnic conflict in Sri Lanka suffered a serious setback after direct talks between the LTTE and the government were postponed indefinitely.