(Tribune News Service) — Thai F-16 fighter jets struck military sites in neighboring Cambodia as a border dispute between the Southeast Asian nations, stretching back decades, erupted in fresh violence that killed at least 11 people.

Both nations accused the other of starting the worst border violence in about 14 years, which also left dozens injured amid clashes in six locations along their frontier.

The eruption Thursday, which included reports of artillery and rocket fire, follows a build up of tensions since a Cambodian soldier was killed in an exchange of gunfire in May and a chain of political events in Bangkok that has threatened the ruling coalition.

Thailand said its fighter jets hit at least three Cambodian army bases near the border in separate airstrikes, and reported that rockets fired from Cambodia killed several civilians. An eight-year old boy was among 11 Thai civilian fatalities, while 24 others were injured, the country’s health ministry said. Acting Prime Minister Phumtham Wechayachai said one soldier has been killed.

There was some variance in the figures reported by authorities in Bangkok, and casualties on the Cambodian side remain unclear.

Thailand’s military operation has been successful but may “take some time,” the army said in a briefing late Thursday. Meanwhile, Cambodian Prime Minister Hun Manet asked the U.N. Security Council to convene an urgent meeting, citing “extremely grave aggressions” that it was forced to respond to in self defence.

“The dispute is escalating rapidly and could turn into a serious conflict if left unattended,” said Jayant Menon, a senior fellow at the ISEAS-Yusof Ishak Institute in Singapore. “Although the conflict is unlikely to spread beyond the two countries, it will disrupt trade and people movement, which will negatively affect the regional economy.”

The fighting comes as both countries face trade threats from U.S. President Donald Trump’s tariff war, with both expected to see exports to the world’s richest consumer market impacted.

The baht, which earlier rose to its highest since February 2022, declined 0.3% to 32.25 per dollar. Thai stocks closed 0.6% lower.

The neighbors have a long history of border tensions, although relations have remained largely stable since the 2011 conflict, which left dozens dead. The last major flare-up centered on the Preah Vihear temple, a longstanding point of contention dating back to French colonial rule.

Much of the contemporary border disputes between the neighbors stem from different maps based on the text of Franco-Siamese treaties of the early 1900s that laid out boundaries between Thailand and Cambodia, then part of the French Indochina.

There are no bilateral talks with Cambodia yet, Phumtham said after a meeting of Thailand’s security council, describing the “clashes” as falling short of a full-scale conflict.

“This is not a declaration of war,” Phumtham said. Still, Thailand ordered evacuations within 31 miles of the border.

Malaysian Prime Minister Anwar Ibrahim, the current chair of regional group Asean, said he aims to speak with the leaders of both countries and called on them to stand down and enter negotiations. “Peace is the only option available,” he told reporters Thursday.

Both the U.S. and China sent advisories to their citizens about the clash, with Beijing saying it was deeply concerned over the attacks.

“Thailand and Cambodia are both China’s friendly neighbors and important members of Asean,” China’s Ministry of Foreign Affairs spokesman Guo Jiakun said in a briefing.

Thailand also ordered the evacuation of civilians from at least four border provinces as a precautionary measure, the Interior Ministry said, while its embassy in Phnom Penh advised citizens to leave the country.

Cambodia’s defense ministry spokesperson Maly Socheata condemned the Thai military’s action, saying Thailand’s use of heavy weapons and deployment of troops “to encroach on Cambodian territory is a clear violation” of international law.

Diplomatic downgrade

Since the clash in May, both countries have massed troops along the frontier and limited land crossings that serve as vital trade routes.

The fighting Thursday came just hours after Thailand expelled Cambodia’s ambassador and recalled its own envoy from Phnom Penh in response to a landmine explosion that injured five Thai soldiers on Wednesday.

In retaliation, Cambodia further downgraded diplomatic ties by withdrawing its diplomats and requesting that Thailand do the same, according to Cambodian state media.

Thailand, a long-standing ally of the U.S., has a military edge over its neighbor.

Cambodia lacks air assets to counter Thailand’s advanced jets, Bloomberg Intelligence analysts Eric Zhu and George Ferguson wrote in a note, but the country possesses Chinese-made KS-1C air defense systems. Those have a reported range of up to 43 miles, according to the Missile Defense Advocacy Alliance.

As well, Cambodia doesn’t have any combat aircraft in its inventory, according to the International Institute for Strategic Studies in London, with its military only flying transport planes and helicopters. Thailand’s air force has two squadrons of modern Lockheed Martin Corp. F-16s and a squadron of Saab Gripen C/Ds, according to IISS.

Thai politics

The dispute has already shaken Thailand’s domestic politics. In early July, a court suspended Prime Minister Paetongtarn Shinawatra pending an investigation into allegations of ethical misconduct in her handling of the border issue.

Paetongtarn had attempted to defuse tensions in a phone call with former Cambodian leader Hun Sen, father of the current premier. But the call was leaked, sparking a backlash at home and protests demanding her resignation. She has until July 31 to submit her defense in the court case.

After the clash in May, Cambodia called for the International Court of Justice in The Hague to help resolve four disputed land areas. Thailand, however, said it does not recognize the court’s jurisdiction in the matter.

Following a landmine incident last week in which a Thai soldier lost his leg, Thailand initiated a diplomatic campaign targeting Cambodia. Bangkok has briefed foreign military attachés and diplomats stationed in the country and is seeking action under the United Nations’ Anti-Personnel Mine Ban Convention, while also engaging in bilateral efforts to resolve the dispute.

With assistance from Jon Herskovitz, Gerry Doyle, Marcus Wong, Kok Leong Chan, James Mayger, Pathom Sangwongwanich and Eduard Gismatullin.

©2025 Bloomberg L.P.

Visit bloomberg.com.

Distributed by Tribune Content Agency, LLC.