Thailand and Cambodia vow to fight on as border clashes kill 13

Thailand and Cambodia vowed to continue fighting on Tuesday as renewed border clashes killed at least 13 people and forced tens of thousands to flee, derailing a US-backed ceasefire that ended deadly combat in July.

Cambodia's military said nine civilians were killed and 20 wounded in the fighting, while Thailand reported four soldiers killed and 68 wounded since clashes resumed Sunday night.

Senate President Hun Sen vowed Cambodia would carry out a fierce fight against Thailand as a second day of widespread combat drove evacuations along the disputed border on Tuesday.

In a statement posted on Facebook and Telegram, Hun Sen claimed Cambodia had refrained from retaliating on Monday following attacks on Sunday but overnight began firing back at Thai forces.

"Cambodia wants peace, but Cambodia is forced to fight back to defend its territory," Hun Sen wrote. The former prime minister, who ruled Cambodia for nearly four decades until 2023 when he was succeeded by his son Hun Manet, is still widely seen as the country's de facto leader.

Thai Prime Minister Anutin Charnvirakul said Tuesday that Cambodia had not contacted Thailand about possible negotiations and the fighting would continue.

"We've got to do what we've got to do," he said. "The government will support all kinds of military operations as planned earlier."

Thailand claimed Cambodia attacked its positions first before Thai troops carried out air strikes along the frontier on Monday, describing the operations as defensive action targeting military installations.

According to Thai military spokesperson Rear Admiral Surasant Kongsiri, such operations would continue "until attacks stop".

Thousands evacuated on both sides

The latest fighting followed a skirmish on Sunday that injured two Thai soldiers and shattered a ceasefire that ended five days of clashes in July over territorial disputes.

That fighting left at least 48 dead on both sides and forced the evacuation of more than 300,000 civilians.

Residents in the disputed border areas began fleeing by the thousands on Monday. The Thai army said almost 500 temporary shelters were set up in four border provinces, accommodating 125,838 people.

An evacuation shelter at a university in Thailand's northeastern city of Surin hosted more than 3,600 people relocated from danger zones. Many were pictured sitting or lying on thin mats, with several setting up small tents on Tuesday.

"We were preparing to evacuate. We hadn't left yet. But when we heard shots, we hurried out immediately," cassava farmer Pan-ngam Kanchangthong said. "I was scared. Who wouldn't be scared of shelling?"

Cambodian authorities said almost 55,000 people have been evacuated, with numbers mounting.

"I felt terrified when I heard the sound of the explosion from the shelling. At that time, I was working at the garment factory," said Vach Neang, 44, a father of seven.

US 'strongly urges' end to hostilities

Cambodia and Thailand have experienced periodic tensions along their land border of more than 800 kilometres.

Some of the disputed territory hosts ancient temples that both nations covet as part of their heritage, including the Ta Krabey temple. Cambodia's Culture Ministry said Thai forces on Tuesday had damaged the site.

Thailand's military, referring to the same 11th-century temple by its Thai name, alleged that Cambodian forces launched rocket attacks into the northeastern province of Surin. It was not possible to independently corroborate either claim.

Malaysia mediated the truce that stopped the fighting in July, and Trump exerted pressure by threatening to deny the two countries trade rights if they did not comply.

US Secretary of State Marco Rubio on Tuesday urged both parties to fulfil their pledges made in the October Kuala Lumpur Peace Accords, including removing heavy weaponry from the border and organising the clearance of land mines.

"We strongly urge the immediate cessation of hostilities, the protection of civilians, and for both sides to return to the de-escalatory measures outlined" in the peace accords, Rubio said in a statement.

At a political event in Pennsylvania late Tuesday, Trump said he would use his influence to end the latest conflict.