A shaky ceasefire between Thailand and Cambodia appeared to be holding Tuesday, as military commanders met despite Bangkok's allegations the truce had been breached with overnight skirmishes.

After peace talks which was held in Malaysia on Monday, both sides agreed an unconditional ceasefire would start at midnight to end fighting over a smattering of ancient temples in disputed zones along their 800-kilometre border.

On Tuesday, the Thai military said Cambodian troops "had launched armed attacks into several areas" in "a clear attempt to undermine mutual trust", but said clashes later stopped.

Cambodia's defence ministry spokeswoman Maly Socheata insisted there had been "no armed clashes against each other in any regions".

Both sides said some morning meetings between rival military commanders along the border -- scheduled as part of the pact -- had gone ahead.

Cambodian leader Hun Manet and Thai acting Prime Minister Phumtham Wechayachai shook hands over the ceasefire deal Monday at peace talks hosted by Malaysia and attended by delegates from the United States and China.

"I saw photos of the two leaders shaking hands," said 32-year-old pharmacy worker Kittisak Sukwilai in the Thai city of Surin -- 50 kilometres from the border.

"The frontline has eased since the ceasefire at 12 midnight," Cambodian Prime Minister Hun Manet said in a Tuesday morning message on Facebook.

Jets, rockets and artillery killed at least 42 people since last Thursday and displaced more than 300,000 -- prompting intervention from US President Donald Trump over the weekend.