By Thomas Escritt and Amy Sawitta Lefevre
THE HAGUE/BANGKOK (Reuters) - A U.N. court ruled in favor of Cambodia on Monday in a long-running dispute with Thailand over jurisdiction of land around an ancient temple, a decision that threatens to add fuel to a deepening political standoff in Bangkok.
The Preah Vihear Temple sits atop an escarpment that forms the border between Thailand and Cambodia. Under a map drawn up when Cambodia was a French colony, the temple is Cambodian but its ownership has dogged ties since Cambodia's independence in the 1950s.
The two sides have exchanged fire around the temple on several occasions in recent years and the dispute has become divisive within Thailand where two broad political factions have been batting for power for years.
The International Court of Justice (ICJ), in clarifying a 1962 decision to award jurisdiction of the temple to Cambodia, ruled that part of the land around it was Cambodia's and Thailand must withdraw its forces from the area.
The verdict could not come at a worse time for Thai Prime Minister Yingluck Shinawatra, who is facing street protests against a government-backed amnesty bill being debated by the upper house Senate.
Opponents say the amnesty is designed to expunge her self-exiled brother and former premier Thaksin Shinawatra's 2008 jail term for abuse of power while he was office, to allow him to return a free man and make a political comeback.
Thaksin promoted close ties with Cambodia when he was prime minister and his enemies have accused him of not defending Thai interests in connection with the border dispute.
Some of the thousands of demonstrators who have been out on the streets of the Thai capital over recent days want to topple Yingluck's government and are accusing it of colluding with Thaksin and Cambodia to "sell" Thai land.
The land they are referring to is 4.6-square km (1.8 sq mile) of scrub surrounding Preah Vihear.
The court said the northern edge of the promontory, upon which Preah Vihear sits, was Cambodian, as agreed in the 1906 treaty between Thailand, then called Siam, and French Cambodia.
"The 1962 judgment required Thailand to withdraw from the whole territory of the promontory ... to Thai territory," judges said in clarifying the original ruling.
The territory they were referring to, however, was just one part of the of the 4.6 sq km that is in dispute, leaving scope for more disagreement.
The court was only able to clarify jurisdiction of promontory that was covered in its 1962 ruling and said it had no authority to rule on rival claims to other land.
Some of the Thai anti-government demonstrators had anticipated the court would rule in Cambodia's favor. At least 1,000 ultra-nationalists among the protesters marched to the Defense Ministry earlier to deliver a letter demanding the military protects what they said was Thai sovereign territory.
That group included former members of the ultra-royalist People's Alliance for Democracy (PAD), which has a track record of whipping up anger to undermine governments that Thaksin has led, both directly and indirectly. The PAD said it did not recognize the court in the Hague.
"This government wants to sell our country and our territory," Chamlong Srimuang, a PAD leader who has helped to topple governments, told reporters prior to the verdict.
"Thais believe in justice but why should we listen to the world court's ruling?"
What concerns Yingluck's government is the PAD's powerful backers among the royalist establishment, which has close ties with military generals who overthrew Thaksin in a 2006 coup and have tacitly backed the PAD in the past.
In a televised address, Yingluck said both countries should strive to reach a satisfactory interpretation of the verdict.
"We share a 800 km long border ... we have to rely on each other," said Yingluck, adding that Thai security forces would still patrol border areas "for the sake of peace and security".
Although both Thailand and Cambodia have promised to respect the court's decision and keep the peace, both have boosted troops at the border, which has been the site of sporadic gun and artillery battles over the past five years, the worst in 2011, when 28 people were killed.
Hundreds of villagers along the border fear that could happen again in the wake of the ruling and many are sheltering in bunkers.
Thailand's government is concerned its opponents will use the court verdict to pile on the pressure.
The amnesty bill is being discussed in the Thai Senate where ruling party whips have indicated the draft might be withdrawn. The opposition fears, however, that the government would withdraw the bill to diffuse tension then re-introduce it when the dust settles.
(Additional reporting by Prak Chan Thul in Phnom Penh; Editing by Martin Petty and Robert Birsel)