A long-simmering border dispute between Thailand and Cambodia spiralled into deadly violence on Thursday, with airstrikes, rockets, and artillery fire exchanged in the contested Emerald Triangle region. At least 11 civilians were killed in Thailand, with both countries trading blame for the escalation.

Thai authorities said Cambodian forces launched rockets and artillery shells early Thursday, striking a petrol station in Sisaket Province. Most of the victims were students inside a convenience store attached to the station, according to provincial officials.

In retaliation, the Thai military scrambled six F-16 fighter jets from Ubon Ratchathani to bomb what it described as two Cambodian military positions. Deputy military spokesperson Ritcha Suksuwanon confirmed the strikes.

The renewed fighting erupted near ancient temples straddling the Thai province of Surin and Cambodia’s Oddar Meanchey. Both countries claim sovereignty over the area, part of the heavily disputed Emerald Triangle where their borders meet Laos. The standoff has flared up repeatedly over the years, including a fatal firefight in May.

According to the Thai military, Thursday’s clashes began when a Cambodian drone was spotted near Ta Muen temple around 7:35 a.m. Thai troops said six armed Cambodian soldiers, one carrying a rocket-propelled grenade, approached their post and opened fire roughly 45 minutes later.

Cambodia disputed that version of events. Defence ministry spokeswoman Maly Socheata accused Thailand of launching an “armed assault,” claiming Cambodian troops acted in self-defence “in full accordance with international law.”

The fallout extended beyond the battlefield. Earlier, Thailand expelled Cambodia’s ambassador and recalled its own envoy after a landmine injured five Thai soldiers. Phnom Penh responded by cutting diplomatic ties to the “lowest level” and ejecting Thai diplomats.

Cambodian Prime Minister Hun Manet called for an emergency UN Security Council meeting, labelling Thailand’s actions “unprovoked military aggression.” Bangkok’s foreign ministry, meanwhile, accused Cambodia of “inhumane” conduct and shut all border crossings.

Thailand’s acting Prime Minister Phumtham Wechayachai called for restraint but pledged to defend national sovereignty. China urged dialogue, while Malaysia, ASEAN’s current chair, appealed for both sides to de-escalate.