After fighting between the two countries over a border dispute broke out in July, both sides have accused each other of breaking the US-backed ceasefire.
Thailand has launched fresh strikes along the border with neighbouring Cambodia. After fighting broke out in July this year, in which dozens of people were killed, both sides accuse each other of breaking a US-baked ceasefire.
The Thai ministry of defence said that more than 35,000 people have left areas near the border for shelters and more are believed to have fled to stay with relatives elsewhere, while Cambodia's Information Minister Neth Pheaktra said that residents of several villages near the border have been evacuated.
Fighting follows exchange of fire on Sunday
The ceasefire was strained in early November after Thai troops were injured by land mines, leading Thailand to announce that it would indefinitely suspend implementation of the agreement. Both sides continue to trade accusations over responsibility, even as they are supposed to be cooperating in getting rid of the mines.
Trump said in mid-November that he’d intervened to preserve the ceasefire as tensions simmered between the two countries.
But another brief episode of fighting took place along the border Sunday, after which both sides said the other fired first. The Thai army said Cambodian fire injured two Thai soldiers and Thai troops retaliated, resulting in an exchange of fire that lasted around 20 minutes. Cambodia said that the Thai side fired first and that its own troops did not retaliate.
On Monday, Thai army spokesperson Maj. Gen. Winthai Suvaree said the Cambodian troops fired first into Thai territory in multiple areas. He said one Thai soldier was killed and four other soldiers were wounded, and civilians were being evacuated from the affected areas.
Thailand used aircraft “to strike military targets in several areas to suppress Cambodian supporting fire attacks," he said.
Cambodian Defence Ministry spokesperson Maly Socheata said the Thai military attacked the Cambodian troops first on Monday, and that Cambodia did not retaliate during the initial attacks.
“Cambodia urges that Thailand immediately stop all hostile activities that threaten peace and stability in the region,” she said.
The prime minister of regional neighbour Malaysia, Anwar Ibrahim, called for restraint in a statement posted to social media and said that his country is ready to supports efforts to avert further fighting.
“Our region cannot afford to see long-standing disputes slip into cycles of confrontation,” he wrote.
Centuries of rivalry lie beneath territorial dispute
Thailand and Cambodia have a history of enmity going back centuries, when they were warring empires.
Their modern territorial claims stem largely from a 1907 map drawn when Cambodia was under French colonial rule, which Thailand has argued is inaccurate.
The International Court of Justice in 1962 awarded sovereignty to Cambodia over an area that included the 1,000-year-old Preah Vihear temple, which still rankles many Thais.
The ceasefire does not spell out a path to resolve the underlying basis of the dispute, the longstanding differences over where the border should run.