EIGHTEEN SOLDIERS WERE KILLED ON MONDAY NIGHT WHEN A FRAGMENTATION MINE BLEW UP THEIR ARMY BUS IN RESTIVE EAST SRI LANKA, HOURS AFTER A TOP TAMIL TIGER ACCUSED THE GOVERNMENT OF RESTARTING THE COUNTRY'S TWO-DECADE CIVIL WAR, REUTERS REPORTED. THE MILITARY BLAMED THE AMBUSH -- THE DEADLIEST SUCH ATTACK SINCE A 2002 TRUCE -- ON THE LIBERATION TIGERS OF TAMIL EELAM (LTTE). SEVEN SOLDIERS AND THREE REBELS WERE KILLED EARLIER IN THE DAY IN THE FIRST ARMY ADVANCE ON REBEL-HELD TERRITORY SINCE THE CEASEFIRE, TAKING THE DAY'S DEATH TOLL TO 28. S. ELILAN, HEAD OF THE TIGERS' POLITICAL WING IN THE EASTERN DISTRICT OF TRINCOMALEE, SAID ARMY TROOPS HAD RESUMED A BID TO ADVANCE TOWARDS REBEL-CONTROLLED LAND IN THE EAST AND HAD FIRED ARTILLERY AND MORTARS AT THEIR TERRITORY IN THE NORTH. "THE CEASEFIRE AGREEMENT HAS BECOME NULL AND VOID AT THE MOMENT," ELILAN TOLD REUTERS BY PHONE FROM TRINCOMALEE, ADDING THAT GOVERNMENT TROOPS WERE ADVANCING TOWARDS THE TAMIL TIGERS' FORWARD DEFENCE LINE IN THE EAST IN A WATER SUPPLY DISPUTE.