Cambodian soldiers have clashed with Thai forces
Britons are being warned to avoid the Thailand-Cambodia border after troop skirmishes in the area.
Two Cambodian soldiers were killed during violent clashes close to the Preah Vihear temple.
The Foreign Office is advising people to stay away from border areas and avoid overland travel between the countries.
Foreign Office minister Bill Rammell said: "As a precautionary measure we have amended our travel advice."
The Foreign Office website has previously warned of political unrest in Thailand and advises Britons to avoid all but essential travel in the far southern provinces of Pattani, Yala, Narathiwat and Songkhla.
Backpacker hotspots in Cambodia which may have attracted people visiting Thailand include the temple the city of Siem Reap and temple of Angkor Wat.
The Preah Vihear temple is another popular attraction but has been closed because of a dispute over the sovereignty of land next to it.