By Helen Regan, Kocha Olarn, Lauren Kent, Olivia Kemp

(CNN) — Armed clashes on the remote, disputed border between Cambodia and Thailand killed at least 12 people on Thursday, in a dramatic escalation of tensions that threatens to erupt into a broader conflict.

Both sides’ forces accuse each other of opening fire Thursday morning. Cambodia then fired rockets on Thai soil, Thailand said, to which it responded with mortars. A Thai fighter jet later dropped two bombs near the road leading to a temple in Cambodian territory, Cambodia said.

The violence comes after months of rising tensions between the two and a day after a Thai soldier lost his leg in a landmine explosion, an incident that cratered relations between Bangkok and Phnom Penh to their lowest level in years. Thailand has since closed all border crossings with Cambodia.

Thailand’s acting prime minister, Phumtham Wechayachai, said that Cambodia fired heavy weapons into Thailand without clear targets, leading to civilian deaths, adding that Thailand will not negotiate with Cambodia until fighting along the border ends.

Cambodia’s Defense Ministry condemned what it called “brutal, barbaric, and violent military aggression,” accusing Thailand of violating international law. The ministry confirmed that a Thai F-16 had dropped two bombs on a road near the ancient Preah Vihear temple, a UNESCO world heritage site.

“Cambodia reserves the right to lawful self-defense and will respond decisively to Thailand’s violent aggression,” the statement said, adding that the armed forces are “fully prepared to defend the kingdom’s sovereignty and its people – whatever the cost.”

Thailand’s 2nd regional military command in the northeast said in a post on Facebook that F-16 fighter jets had been deployed in two areas. It also claimed to have “destroyed” two Cambodian regional military support units. Army spokesperson Col. Richa Suksuwanont said the strikes were aimed only at military targets.

At least 12 people in three Thai provinces, including 11 civilians and one Thai soldier, were killed in Thursday’s violence, while a further 31 people were injured, according Thailand’s Ministry of Public Health. An 8-year-old boy was among those killed, the Thai military earlier said.

Cambodian authorities did not immediately report of any fatalities on their side.

Among the casualties were six people killed when a Cambodian rocket hit a busy gas station close to the border in Kantharalak, Sisaket province, the Thai military said. Social media video, geolocated by CNN to Kantharalak, showed several wounded people outside a heavily damaged 7-Eleven convenience store and gas station, with smoke billowing in the background.

Thailand also accused Cambodian troops of firing two BM-21 rockets into a civilian area in Kap Choeng district of Surin province, in Thailand’s northeast. Bangkok’s Ministry of Foreign Affairs said Cambodian attacks on civilian areas continued throughout Thursday, including at a hospital in Surin.

Residents of Surin could be seen running for cover and taking shelter in bunkers amid the sound of gunfire, in video from Thai PBS.

A motorcycle shop keeper in Surin, Komsan Jaipeng, told CNN that when the clashes started, he saw many school children rushing to escape. Komsan was opening up his shop when he first heard a boom Thursday morning.

“I told my wife that we are not going home tonight, we will stay at least a night at this shelter here. Our house (is) about 7 to 8 kilometers from the border,” he said from Phanom Dong Rak district. Komsan said he had prepared a bag of items for more than a month now, including spare clothes and phone chargers. “I hope this ends quickly. I have not been in this situation before,” he added.

Across the disputed border in the Cambodian province of Preah Vihear, Chhan Rorn Yon told CNN that his neighbors have sought refuge in a pagoda in a nearby town but he will remain in his village of Sa Em.

“I am so concerned that the bomb drop and the bullet will kill us,” the 45-year-old farmer said from Sa Em, 10 kilometers (6 miles) north from the conflict area where the shooting first erupted Thursday morning. “I don’t want to experience this… I am extremely concerned. I am worried for my people, my children, my relatives and especially for the troops who fight.”

Thailand’s military said it condemns “violent acts against civilian targets by the Cambodian side and is prepared to take military action to the fullest extent to protect its sovereignty and its people from such inhumane actions.”

It accused Cambodia of violating both its sovereignty and international law, claiming it laid landmines within Thai territory on the disputed border.

Meanwhile, Cambodian Prime Minister Hun Manet called on the United Nations Security Council to convene an “urgent meeting” to “stop Thailand’s aggression.”

In recent decades, Thailand and Cambodia have had a complicated relationship of both cooperation and rivalry. The two countries share a 500-mile (800-kilometer) land border – largely mapped by the French when they controlled Cambodia as a colony – that has periodically seen military clashes and been a source of tension.

In 2011, Thai and Cambodian troops clashed in an area surrounding the 11th-century Preah Vihear temple, displacing thousands of people on both sides and killing at least 20 people.

How the latest escalation began

The recent flare-up came after five Thai soldiers were injured in a landmine explosion on Wednesday, with the incident prompting Thailand to downgrade diplomatic relations with Cambodia.

Early Thursday morning, Thailand’s military said Cambodian troops fired at a Thai army base in an area near the ancient Ta Muen Thom Temple, also called Ta Moan Thom Temple, which lies about 250 miles (400 kilometers) northeast of Bangkok in disputed territory in the south of Thailand’s Surin province and in Cambodia’s northwest.

Thailand said Cambodia had deployed a drone in front of the temple, before sending troops in with weapons. Clashes then erupted along the entire border region, in at least six locations, with small arms and heavy weapons used, according to Thailand’s military. That led to civilian casualties, damaged homes and livestock, and prompted the evacuation of residents nearby.

Cambodia has disputed that account. A Cambodian Defense Ministry spokesperson said its troops acted in self-defense after an unprovoked incursion from Thai soldiers.

Tensions between the two neighbors had already soured in May, when a Cambodian soldier was killed during a clash between Thai and Cambodian troops in which both sides opened fire in another contested border area of the Emerald Triangle, where Cambodia, Thailand and Laos meet.

The dispute has since had major political consequences for Thailand and stoked nationalist fervor in both countries.

Thailand’s Prime Minister Paetongtarn Shinawatra was suspended from duties earlier this month and could face dismissal after the leak of a phone call she had with Hun Sen, in which she appeared to criticize her own army’s actions in the dispute.

The ongoing conflict is “likely to get worse before it gets better” and the next few days could see more “confrontation, clashes, escalation,” Thitinan Pongsudhirak, a professor of political science at Chulalongkorn University in Bangkok, told CNN. “Each side has so much pent-up tension.”

This story has been updated with additional developments.

The-CNN-Wire
™ & © 2025 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.