Thailand has imposed an immediate ban on drone operations in 14 areas along its border with Cambodia, where military clashes have escalated into the combat debut of the Royal Thai Air Force's Gripen fighters.

Experts say the ceasefire agreement brokered in Putrajaya was a win for Malaysia premier Anwar Ibrahim and ASEAN. With clashes reportedly erupting early Tuesday morning, however, observation teams are urgently needed on the ground.

A ceasefire between Thailand and Cambodia held and military commanders from both sides met to discuss measures to maintain the truce, as some residents along the disputed frontier trickled back home after five days of intense fighting.

A Cambodian government official has praised U.S. President Donald Trump for "bringing about peace" after Thailand and Cambodia agreed to a cease-fire starting at midnight local time on Monday.

After Bangkok rejected what it called the "baseless accusation" it had used chemical weapons over Cambodia during the Southeast Asian neighbours' bloodiest military clashes in decades, a months-old photo resurfaced in posts falsely claiming it showed the Thai air force using a "poisonous smoke weapon".