Thai soldiers flew a drone carrying the national flag over a conflict zone with Cambodia.

Footage shows the aerial machine parading the fluttering Thai flag as it zipped over a recently recaptured high-ground base in Ubon Ratchani province, on December 15.

The Second Army Area said: 'A symbol of sovereignty, honoured through the mission of an unmanned aerial system, reaffirming Thailand's unwavering commitment to defending its land through the courage and sacrifice of Thai warrior heroes. Thailand's sovereignty and territorial integrity are non-negotiable and shall never be violated.'

The Royal Thai Army said it also seized a large cache of Chinese-made weapons from Hill 500 after reclaiming the area.

Fighting flared up earlier this month as the Thai army claimed Cambodian troops fired on a Thai engineering team building an access road in a disputed border area.

At least 15 Thai soldiers and one civilian have been killed since fighting resumed. In Cambodia, at least 11 civilians have died, while the number of soldiers dead is believed to be much higher.

Around 600,000 people have been displaced on both sides of the border.

Cambodia's assault has largely been wayward, unguided rockets fired indiscriminately into Thai territory, while Thailand has used precision drone strikes and fighter jet strikes on military sites.

Former Khmer Rouge henchman and Cambodian dictator Hun Sen has repeatedly claimed that he wants peace and that Thailand is the aggressor.

Thai officials claim the ongoing border confrontations are a threat to national security, and the areas must be secured.