Thai and Cambodian troops clashed for a fourth straight day on Monday over a disputed border area surrounding a 900-year-old mountaintop temple, deepening political uncertainty in Bangkok and prompting Cambodia to urge UN intervention.
Several hours of shelling and machine gun fire subsided at around 11 a.m. (11 p.m. EST on Sunday), creating an uneasy peace in the 4.6-sq-km (two-sq-mile) contested area around the Preah Vihear temple claimed by both Southeast Asian neighbors.
Cambodia's government said Monday's fighting had killed five people and wounded 45 others on its side of the border. It did not specify whether the casualties were troops or civilians.
Both sides blame the other for sparking clashes that have killed at least two Thais and eight Cambodians since Friday and unleashed nationalist passions in Bangkok, energizing "yellowshirt" protesters demanding Thailand's government step down.
Reasons behind the fighting remain murky. Some analysts reckon hawkish Thai generals and nationalist allies may be trying to topple Thailand's government or even create a pretext to stage another coup and cancel elections expected this year.
Others say it may be a simple breakdown in communication channels at a time of strained relations over Cambodia's flying of a national flag in the disputed area and laying of a stone tablet inscribed with "This is Cambodia".
In Phum Saron, an evacuated village in Thailand's Si Sa Ket province where Cambodian artillery struck several homes and a school on Sunday, Thai soldiers guarded buildings and said it was unclear if more fighting loomed.
On the Cambodian side of the frontier, pigs and chickens roamed deserted villages. Schools and temples were turned into makeshift refugee centers. Naked children played as people collected firewood or queued for handouts of rice and water.
Several trucks each carrying at least 100 Cambodian infantry soldiers were seen racing toward the conflict zone.
Cambodian Prime Minister Hun Sen called on the UN Security Council to convene an urgent meeting, accusing Thailand of "repeated acts of aggression" that have killed Cambodians and caused a wing of the temple to collapse.
In a speech in the Cambodian capital Phnom Penh, Hun Sen directly addressed his Thai counterpart.
"We will go to the UN Security Council whether you like it or not," he said during a university graduation ceremony, calling on the United Nations to deploy peacekeeping troops to the area. "The armed clash is threatening regional security."
Thai Prime Minister Abhisit Vejjajiva wrote to the Security Council, saying Cambodia was trying to internationalize a bilateral issue, accusing its troops of launching attacks that were "pre-mediated and well-planned in advance".
Thai troops "had no choice but to exercise the inherent right of self defense," Abhisit said.
UN Secretary-General Ban Ki-moon said in a statement he was "deeply concerned" and urged both sides to cease fire and find a "lasting solution" to the dispute, echoing a similar statement from Washington over the weekend.
The Association of South East Asian Nations (ASEAN) dispatched Indonesian Foreign Minister Marty Natalegawa to Cambodia on Monday in a bid to defuse the crisis. He was scheduled to meet with Thai government officials in Bangkok on Tuesday.
Natalegawa called for dialogue and for both sides to honor a ceasefire agreed on Friday to protect ASEAN's integrity ahead of the formation of its European Union-style community.
"On the eve of an ASEAN community in 2015, guns must be silent in Southeast Asia," he told reporters in Phnom Penh.
The dispute threatens to worsen hostility between Thai political factions ahead of the expected election this year.
Thailand's police chief said he would seek cabinet approval on Tuesday to impose the Internal Security Act to enable security forces to stop protesters from occupying government buildings in Bangkok in a planned demonstration on Friday.
The "yellow shirts", whose crippling rallies helped to bring Abhisit to power, have turned against him in recent weeks, calling for him to take a tougher line against Cambodia.
In 2008, they occupied state offices for three months and blockaded Bangkok's main airport until a court expelled a government allied with former Prime Minister Thaksin Shinawatra, a step that paved the way for Abhisit to take power.
"I don't think this will look good for Abhisit's government, especially as we are heading toward elections," said Pavin Chachavalpongpun, a fellow at the Institute of Southeast Asian Studies in Singapore.
The clashes pushed down shares in Thai firms with businesses in Cambodia, led by a 1.8 percent loss in satellite firm Thaicom, with its telecom service in Cambodia contributing 10 percent of revenue.
The temple, known as Preah Vihear, or "Mountain of the Sacred Temple", in Cambodia and Khao Phra Viharn in Thailand, sits on a triangular plateau that forms a natural border.
Both sides have been locked in a standoff since July 2008, when Preah Vihear was granted UNESCO World Heritage status, which Thailand opposed on grounds that territory around the temple had never been demarcated.
The International Court of Justice in 1962 awarded the temple to Cambodia, which uses a century-old French map as the basis for its territorial claims, but the ruling failed to determine ownership of the scrub next to it.