Bangkok  - Thai police on Saturday blocked thousands of protestors from an area on the Cambodian border where a dispute over an 11th-century Hindu temple has strained bilateral ties and almost sparked a war last year.

An estimated 500 buses carrying about 4,000 members of the People's Alliance for Democracy (PAD) were blocked at Phumisarol town by 1,000 police and kept from entering Phra Viharn National Park in Sisaket province, about 450 kilometres north-east of Bangkok, the Bangkok Post online news service reported.

The PAD led anti-government protests last year that culminated in the seizure of Bangkok's two airports and the toppling of the previous administration, led by the People Power Party (PPP).

The movement is staunchly opposed to the return to power of ousted premier Thaksin Shinawatra, who was overthrown in a coup in September 2006 but was the main political force behind the PPP.

PAD leaders objected to the PPP's decision last year to support Cambodia's bid to list the Preah Vihear temple as a UNESCO World Heritage Site, claiming the move was motivated by Thaksin's vested business interests in Cambodia.

Despite their protests, the temple ruins were granted heritage status, sparking protests and an incursion into Cambodian territory by some PAD activists.

Their arrests by Cambodian soldiers and Thailand's aggressive response to the incident almost sparked a border war in July last year.

The historical site has been the subject of diplomatic tensions between Thailand and Cambodia for decades.

An ownership dispute over the temple, which is perched on a cliff defining the Thai-Cambodian border, was settled by an International Court ruling in the Hague in the mid-1950s, but the court failed to rule on the ownership of land adjacent to the temple.

Thailand insists that this land is still under dispute and the granting of UNESCO heritage site status was premature. (dpa)