Governing party says it has downgraded ties with Cambodia after a landmine incident that injured a Thai soldier.

Thailand has recalled its ambassador to Cambodia and will expel Cambodia’s ambassador, the governing Pheu Thai Party said, following a landmine incident that injured a Thai soldier along the disputed border between the two countries.

The Thai Ministry of Foreign Affairs has lodged a formal protest with Cambodia, saying the landmines found in the area were newly deployed and had not been encountered during previous patrols, the party said on social media on Wednesday.

Thailand has downgraded diplomatic relations with Cambodia, it said.

Thailand’s foreign ministry said it had yet to be informed of the decision to recall the Thai envoy and the plan to expel Cambodia’s ambassador.

The government has also ordered the closure of all border checkpoints under the jurisdiction of Thailand’s Second Army, the Pheu Thai Party said.

“Tourists are strictly prohibited from entering these border areas,” it said.

A long-running territorial row in an area known as the Emerald Triangle, where the borders of both countries and Laos meet, boiled over into military clashes in May that left one Cambodian soldier dead.

Since then, the two sides have traded barbs and tit-for-tat retaliatory measures.

In the landmine incident on Wednesday, the Thai soldier sustained injuries and lost his right leg, the Pheu Thai Party said.

Earlier, Thailand accused Cambodia of placing landmines on the Thai side of the disputed border area after three soldiers were injured, but Phnom Penh denied the claim and said the soldiers had veered off agreed routes and triggered a mine left behind from decades of war.

Thai authorities said the soldiers were injured, with one losing a foot, by a landmine while on a patrol on July 16 on the Thai side of the disputed border area between Ubon Ratchathani and Cambodia’s Preah Vihear Province.

Cambodia’s foreign ministry denied that new mines had been planted, and said in a statement on Monday that the Thai soldiers deviated from agreed patrol routes into Cambodian territory and into areas that contain unexploded landmines.

The country is littered with landmines laid during decades of war.

The continuing border dispute has soured relations between the two countries, prompting the closure of border crossings, and Cambodia blocking imports of fuel and gas, as well as fruit and vegetables, from Thailand.

It also triggered a domestic political crisis in Thailand, where Prime Minister Paetongtarn Shinawatra has been suspended from office pending an ethics probe over her conduct during the row.

A diplomatic call between Paetongtarn and Hun Sen, Cambodia’s former longtime ruler and father of Cambodian Prime Minister Hun Manet, was leaked from the Cambodian side, prompting a judicial investigation.

Last week, Hun Manet announced that Cambodia would start conscripting civilians next year, activating a long-dormant mandatory draft law.

He said the tensions with Thailand meant conscription was needed, and the defence budget may also be increased.