The Cambodian government has demanded that Thailand release 20 of its soldiers who it said were captured eight hours into a ceasefire between the two neighbors — which was on Thursday holding into a third day.

"We appeal to the Thai side to promptly return all 20 of our forces, including other forces if any are under Thai control," said Cambodian Prime Minister Hun Manet.

"We will do our best to continue negotiations with the Thai side in order to bring all our soldiers back home safely and as soon possible," added a spokeswoman for the Cambodian Defense Ministry.

Thailand says it will release captured Cambodian soldiers

The Thai government said on Wednesday that the detained soldiers were being treated in line with international humanitarian law and military regulations, and would be returned when the border situation stabilizes.

"We are investigating them to verify the facts," said Thailand's Acting Prime Minister Phumtham Wechayachai. "After this is finished, they will be released."

Thai Rear Admiral Surasant Kongsiri stressed that the Thai military had not violated the ceasefire agreement and said the 20 Cambodian troops had surrendered at around 7.50 a.m. local time on Tuesday (0030 GMT), almost eight hours into the ceasefire, with two requiring medical treatment.

Cambodian Lieutenant General Rath Dararoth said one other Cambodian soldier had died in Thai custody since the ceasefire. He did not provide further details except to say that his body had been returned.

Thailand-Cambodia ceasefire appears to hold

Thailand and Cambodia agreed a truce on Tuesday following five days of clashes that killed at least 43 people on both sides and displaced over 300,000 — the latest eruption of a long-standing dispute over temples along their 800-kilometer (500-mile) border.

And despite accusations of ceasefire breaches from both sides on Wednesday, the truce appeared to be holding on Thursday.

United Nations rights chief Volker Türk urged the warring parties to implement their ceasefire deal in full and take rapid steps to build confidence and peace.

"This crucial agreement must be fully respected, in good faith, by both sides, as diplomatic efforts continue, in a bid to resolve the root causes of the conflict," he said.

Those roots include the disputed ownership of the ancient Hindu temple Ta Moan Thom and the 11th-century temple Preah Vihear.

The current truce, which was agreed in Malaysia on Monday, comes after US President Donald Trump held phone calls with the leaders of both Thailand and Cambodia and threatened both with 36% tariffs and no trade deal if the fighting continued.

US Commerce Secretary Howard Lutnick said early on Thursday that trade deals had now been made with both countries ahead of the August 1 tariff deadline.

Edited by: Elizabeth Schumacher