Thailand warned its border conflict with Cambodia could “escalate into a state of war” as fighting expanded to new areas and both sides exchanged heated rhetoric on a second day of clashes on Friday.
At least 15 people have been killed in Thailand and one in Cambodia and tens of thousands of people have been displaced on both sides of the contested border.
Acting prime minister Phumtham Wechayachai of Thailand claimed Cambodia had deployed heavy weapons on multiple fronts and Bangkok was defending its territory.
“The current situation involves acts of intrusion and aggression that are causing harm to the people’s lives. The situation has intensified and could escalate into a state of war. At present, it’s a confrontation involving heavy weapons,” he told reporters.
Fighting expanded to 12 locations on Friday, the Thai military said, up from six the previous day when they first erupted.
The two sides blamed each other for starting the conflict amid continued fighting, with Bangkok accusing the rival nation of deliberately targeting civilians and Phnom Penh alleging that Thailand was using cluster munitions, an ordnance banned by an international treaty.
The Southeast Asian nations contest several stretches of their 817km land border – partly drawn by Cambodia’s French colonial rulers over a century ago – which passes near several archaeologically important religious sites claimed by both countries.

The US, a longtime ally of Thailand, urged an immediate end to the ongoing hostilities. State Department deputy spokesman Tommy Pigott said that Washington was “gravely concerned by the escalating violence along the Thailand-Cambodia border and deeply saddened by reports of harm to civilians”.
“The US urges an immediate cessation of hostilities, protection of civilians and a peaceful resolution of the conflict,” he added.
China said that it was “deeply concerned” about the violent clashes and would “continue in its own way to do its best to promote peace and dialogue”.
The UN Security Council was due to meet on Friday to discuss the conflict.

Thailand rejected the possibility of third-party mediation to end the conflict, insisting that Phnom Penh cease attacks and resolve the situation through bilateral talks.
“I don’t think we need any mediation from a third country yet,” Thai foreign ministry spokesperson Nikorndej Balankura told Reuters.
The remarks came after Malaysian prime minister Anwar Ibrahim, chair of the Asean bloc which includes both Thailand and Cambodia, said he welcomed “the positive signals and willingness shown by both Bangkok and Phnom Penh to consider this path forward”.

Thailand has evacuated about 100,000 people from border areas to temporary shelters in four affected border provinces.
Cambodian authorities have moved more than 4,000 people to safety.
The Thai military reported clashes on Friday in Chong Bok and Phu Makhuea in the Ubon Ratchathani province, Phanom Dong Rak in Surin, and near the ancient Ta Muen Thom temple.
In Cambodia, a man died after a Thai rocket struck a Buddhist pagoda where he had taken shelter.

In Surin, around 600 people sought refuge inside a university gymnasium roughly 80km from the border. Families huddled on mats and blankets, sharing space and queuing patiently for food and water.
Among them was seamstress Pornpan Sooksai, who arrived with four cats nestled in two fabric carriers. “I just heard, boom, boom. We’d already prepared the cages, clothes and everything, so we ran and carried our things to the car. I was frightened, scared,” she said, referring to the shelling that began near her home close to the Ta Muen Thom temple on Thursday.
Rattana Meeying, another evacuee, lived through the last major border clash in 2011. This time, she said, felt different.
“Children, old people, were hit out of the blue,” she said. “I never imagined it would be this violent.”