Si Sa Ket, Thailand: Thailand’s acting Prime Minister Phumtham Wechayachai on Friday warned that ongoing border clashes with Cambodia “could develop into war,” after a second day of fighting forced over 138,000 people to flee Thai border regions.

A long-standing territorial dispute erupted into a full-scale confrontation on Thursday, involving jets, artillery, tanks and ground troops. The clashes prompted the United Nations Security Council to schedule an emergency meeting later Friday.

Casualties mount as strikes continue

From Cambodia’s side, artillery fire persisted Friday. Officials in Oddar Meanchey province reported one civilian — a 70-year-old man — killed and five others wounded.

Thailand’s health ministry confirmed 15 deaths — 14 civilians and one soldier — and 46 wounded, including 15 troops. On Friday evening, a Thai military border commander imposed martial law in eight border districts, citing “Cambodia's use of force to enter Thai territory”.

Thai PM signals military readiness

“We have tried to compromise as we are neighbours, but we have now instructed the Thai military to act immediately in case of urgency,” said Phumtham.

“If the situation escalates, it could develop into war — though for now, it remains limited to clashes,” he told reporters in Bangkok.

The Thai army reported that fighting resumed around 4:00 am Friday (2100 GMT Thursday) in three areas, with Cambodian forces using heavy weapons, field artillery, and BM-21 rocket systems. Thai troops responded “with appropriate supporting fire”.

Thailand open to dialogue as ASEAN watches

By afternoon, Thai foreign ministry spokesman Nikorndej Balankura told AFP there were signs of de-escalation and expressed readiness for talks, potentially involving Malaysia.

“We are ready, if Cambodia would like to settle this matter via diplomatic channels, bilaterally, or even through Malaysia, we are ready to do that. But so far we have not had any response,” Nikorndej told AFP.

Malaysia currently chairs the ASEAN regional bloc, which includes both Thailand and Cambodia.

Cambodia accuses Thailand of backing out

Cambodian Prime Minister Hun Manet, however, accused Thailand of withdrawing from a proposed ceasefire. In a statement, he said he was waiting for Bangkok’s “genuine willingness” to de-escalate.

Chinese Foreign Minister Wang Yi also voiced concern, calling the casualties “deeply distressing” and urging the situation be “approached calmly and handled properly”.

Civilians flee as tensions escalate

While Cambodia has not released official casualty figures, AFP journalists in Oddar Meanchey saw four wounded soldiers and three injured civilians receiving treatment. The soldiers were reportedly wounded Thursday, and the civilians said they were hit by shrapnel.

In Samraong, a Cambodian town 20 kilometres from the border, families were seen fleeing amid gunfire.

“I live very close to the border. We are scared,” 41-year-old Pro Bak told AFP, as he evacuated his wife and children to a nearby Buddhist temple.

A conflict rooted in a contested frontier

The current violence marks a significant escalation in a long-simmering dispute over an 800-kilometre shared border. Previous clashes between 2008 and 2011 left at least 28 dead and tens of thousands displaced.

Although a 2013 UN court ruling settled the issue for over a decade, tensions reignited in May when a Cambodian soldier was killed in a skirmish.

Thursday’s fighting centred on six locations, including two ancient temples. Thailand accused Cambodia of targeting civilian infrastructure — including a hospital and a petrol station — while Cambodia claimed Thai F-16 jets bombed military targets. Both sides blamed each other for initiating hostilities.