Sri Lankan government troops and Tamil Tiger rebels exchanged gunfire and skirmished at sea on Sunday, bringing to an end a four-day lull in fighting around the besieged Jaffna peninsula, according to Reuters. Residents reported brief exchanges of gunfire south of Jaffna near a vital road artery as well as a volley of artillery fire from both sides. A military spokesman said Sri Lankan naval vessels and "Sea Tigers" from the Liberation Tigers of Tamil Eelam (LTTE) also clashed at sea and that one rebel boat had been sunk. In a statement, the national security media centre said a large vessel carrying weapons and ammunition had been sunk 100 miles (160 kms) off Kalmunai. It said the unflagged vessel had opened fire on a Sri Lankan navy ship when ordered to halt and was subsequently sunk by navy and air force fire. "Large quantities of weapons and ammunition including artillery guns had submerged with the vessel," the statement said, without saying how this may have been confirmed. A response from the LTTE was not immediately available. Norwegian mediators are trying to fix a date for direct talks between the government and LTTE rebels after both sides announced last week they were ready to resume talks after a gap of five months.