Thailand banned drones and kites amid espionage fears during border clashes with Cambodia.

Nakhon Ratchasima Governor Anuphong Suksomnit implemented the measure on Wednesday following a surge of unidentified drones allegedly flying over northeast Thailand.

Authorities, citing ongoing clashes along the Thai-Cambodia border, feared the drones were being used for surveillance and moved to push flight restrictions.

The ban also extends to kites and other items that could threaten air security, they added.

Farmers who use drones for agricultural purposes were urged to comply and wait for further guidelines to obtain drone permits.

The move comes after police warned residents in northeast Thailand to monitor Russian tourists, following reports that the Cambodian army had enlisted foreign agents to operate in the region.

Territorial clashes flared up earlier this year before a brief ceasefire, but started again this month when Cambodian troops are said to have fired on a Thai engineering team building an access road in a disputed border area.

In the most recent battles, at least 21 Thai soldiers and one civilian have been killed. In Cambodia, the number of military fatalities is believed to be much higher, though regime chiefs have not revealed the actual figure.

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, including an attack on July 24 that killed eight people and injured 13 others. 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.