The tank screeches as it rolls into the ad-hoc military base before four battle-weary soldiers jump out to re-inspect the hefty vehicle.

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".

The Thailand-Cambodia border, where fighting has raged since last week, was calm on Tuesday following a ceasefire deal and military commanders from both sides are set to meet for talks later in the day,

The State Department raised both advisories to Level 2 on July 25, citing the “risk of unrest” in Thailand and crime and landmines in Cambodia.

A deadly military clash along Thailand and Cambodia's shared border is escalating, with airstrikes carried out by the Thai army.