50 artillery shells landed on Thai territory near the base of KPNLF guerrillas. In a broadcast monitored in Bangkok, guerrillas loyal to Prince Sihanouk said Vietnam had eight battalions within striking distance of their stronghold at Tatum, a settlement just inside Cambodia's northern border. Thai troops had been put on full alert to prevent a spillover of the fighting. Late May-early June: the Vietnamese Navy repeatedly attacked Thai fishing trawlers off the Vietnamese coast, resulting in the deaths of three Thai fishermen. 10 August: Vietnamese infantry, APCs and artillery stationed north of Ampil Camp shelled Nong Chan and Ampil, forcing 10,000 KPNLF troops and civilian refugees to flee into Thailand. Since the 15 April battle for Ampil, the KPNLF had regained control of the camp. 28 October: Thai Border Patrol Police capture 5 unarmed Vietnamese infantry regulars who had entered Thailand near Ban Wang Mon southeast of Aranyaprathet, reportedly looking for food. 6 November: Vietnamese troops attacked a lightly manned Thai Border Patrol outpost near Surin on the border. Two Thai soldiers were killed, 25 wounded and 5 missing in fighting for control of Hill 424 at Traveng, 180 miles northeast of Bangkok. About 100 soldiers from the PAVN 73rd Regiment pushed about a mile into Thai territory but were later forced back into Cambodia by Thai forces. A Thai military source said the Vietnamese crossed the border in pursuit of Khmer Rouge guerrillas. 18–26 November: Nong Chan Refugee Camp was attacked by over 2,000 soldiers of the PAVN 9th Division and fell after a week of fighting, during which 3 Vietnamese captains and 66 Cambodian soldiers of the KPRAF were killed. 30,000 civilians were moved to evacuation Site 3 (Ang Sila) then to Site 6 (Prey Chan). 8 December: Nam Yuen, a small camp in eastern Thailand near the border with Laos, was shelled and evacuated. 11 December: Sok Sann was shelled and evacuated. 25 December: Nong Samet Refugee Camp was attacked at dawn. The entire Vietnamese 9th Infantry Division (over 4000 men) plus 18 artillery pieces and 27 T-54 tanks and armoured personnel carriers participated in this assault. The Vietnamese deployed both 105mm and 130mm howitzers, Soviet-built M-46 field guns with a range of up to 27 kilometres. KPNLAF guerrillas claimed that 14 Vietnamese tanks and APCs were destroyed during the fighting. An estimated 55 resistance fighters and 63 civilians died in the assault and 60,000 civilians were