BAN NONGKANA, Thailand: Heavy fighting erupted Sunday for a third day between Thai and Cambodian troops, with gunfire and explosions heard on both sides of the disputed border as the United Nations renewed calls for a lasting solution to the conflict. The clashes, which have killed 11 people on both sides since Friday, started at 0950 A.M.(0250 GMT) with the sound of sustained artillery explosions. Some villagers on the Thai side were loading pick-up trucks with family and pets and fleeing, while others packed into newly dug bunkers or hid in large concrete shelters. UN Secretary General Ban Ki-moon called for maximum restraint, “serious dialogue” and an “effective and verifiable” solution to a conflict he had earlier urged the Association of South East Asian Nations (ASEAN) to help settle after four days of deadly clashes in early February. The reasons behind the clashes are not clear with the neighbors exchanging blame, but relations with Cambodia have become a divisive issue in Thailand's fractious domestic politics. There were no immediate reports of any new casualties in the latest flare-up of the worst border fighting in nearly two decades. As well as the 11 soldiers from both sides killed in the first two days, 43 were wounded in the clashes around the Ta Moan and Ta Krabey temples, about 150 km west of the 900-year-old Preah Vihear temple which saw a deadly four-day standoff in February. Thousands of people evacuated from the villages were sheltering in camps on either side of the porous border where villagers from both countries, many of the whom share the same ethnic makeup, mingle and trade each day. Many were returning to their homes in trucks before renewed fighting erupted and regular explosions thundered throughout the rustic border villages, many dotted with Thai flags denoting Thailand's claim to sovereignty of the area. Three Cambodian soldiers and one Thai soldier were killed Saturday in a pre-dawn clash west of Ta Krabey that lasted about five hours, a day after four Thai and three Cambodian soldiers died in battle. Cambodia's Defense Ministry earlier condemned Thailand for launching attacks aimed at taking control of the two temples and accused its army of firing 75 and 105 mm shells “loaded with poisonous gas”. Thailand said the claims were “groundless”. Thai Prime Minister Abhisit Vejjajiva accused Cambodia of trying to internationalise the dispute and insisted bilateral negotiations were the correct means to restore peace and outside help was not required. “It's the duty of all Thai people to defend our sovereignty,” he said during his weekly televised address Sunday. “We must not fall into Cambodia's trap in trying to spread a picture of conflict, or say the conflict is unsolvable through bilateral talks. We will definitely not let that happen.” Sovereignty over the ancient, stone-walled temples and the jungle of the Dangrek Mountains surrounding them has been in dispute since the withdrawal of the French from Cambodia in the 1950s.