Cambodian prime minister Hun Sen has called on the United Nations to intervene in an ongoing and deadly dispute with Thailand over the 900-year-old Preah Vihear temple.

The Cambodian government says the latest round of fighting, which broke out on Friday, has killed several people, including a local tourist who was apparently taking photos of the temple.

Hun Sen has described the clashes between troops on the Thailand-Cambodian border as "a big skirmish or a small war" and claims Thailand is trying to capture the disputed 4.6 square kilometres around the border temple.

He says the UN should send peacekeepers to provide a buffer between the two nations to prevent further fighting.

The temple was ruled Cambodian territory by an international court in the 1960s, but when it was declared a World Heritage site in 2008, a long-festering disagreement flared about its ownership and the territory around it.

Since then, opposing troops have been stationed there, with both countries vowing to protect their sovereignty.

Thailand will now ask UNESCO to take it off the World Heritage list.

A group of Thai nationalists rallying in Bangkok over the issue has demanded Thailand withdraw from the World Heritage committee.

Cambodia says the temple has been heavily damaged in the fighting, but Thailand says that claim is "propaganda".