Thailand accused Cambodia of refusing to negotiate to resolve a border dispute that led to the fourth straight day of fierce clashes Monday, as Phnom Penh said that only U.N. peacekeepers can stop the fighting near an 11th century temple.

Cambodia says the crumbling stone temple — classified as a World Heritage site — has been heavily damaged during several bursts of artillery fire over four days. The extent of the damage could not be confirmed.

The exchange of cross-border fire is highly unusual among members of the 10-member Association of Southeast Asian Nations, and has raised tensions in a region known for its stability.

Preah Vihear temple — which is in northern Cambodia, several hundred feet (meters) from the border with Thailand — has fueled nationalism in both countries for decades and conflict over it has sparked sporadic, brief battles in recent years. Repeated clashes over several days like this month's have been rare, however.

A one-hour clash Monday morning stopped after both sides agreed to an unofficial cease-fire. Fighting has erupted daily since Friday, leaving at least seven dead and dozens wounded.

In 1962, the World Court determined that the Preah Vihear temple belonged to Cambodia. Thai nationalists have never accepted that ruling, and land around the temple remains in dispute.

In recent months, Thailand's embattled Prime Minister Abhisit Vejjajiva has come under intense criticism recently from ultra nationalist groups who claim he has shown weakness in his dealings with Cambodia and hasn't done enough to protect Thailand's sovereignty in the border dispute.

The fighting at the border comes as those groups stage a prolonged protest outside Abhisit's offices in Bangkok to demand he step down over the border issue and a litany of other complaints.

Cambodian Prime Minister Hun Sen reiterated a call Monday for an urgent meeting of the U.N. Security Council, warning that the fighting poses a threat to regional stability.

"We need the United Nations to send forces here and create a buffer zone to guarantee that there is no more fighting," Hun Sen said. "There is only one resolution to solve this issue: It is to ask the U.N. Security Council for an immediate intervention."

U.N. diplomats heading into a regularly scheduled Security Council briefing about the Congo on Monday said the border dispute was expected to be discussed. But there was no sign that any action would be taken.

U.S. State Department spokesman P.J. Crowley said that Brazil in its capacity as rotating council president will submit the issue to the council — as requested by Cambodia. He said the U.S. had "not yet decided" what its position would be.

Thailand, however, insisted that the best solution was for the two neighbors to talk themselves, and a military spokesman accused Cambodia of refusing to speak.

"We are not closing communication channels. But we are not going to be the only one trying to establish talks," Col. Sansern Kaewkamnerd told The Associated Press. "If they keep firing we have to fire back. We are not going to stop at that point and try to ask to talk."

Crowley said the U.S. had raised its concerns over the clash to senior officials of both Thailand and Cambodia and was urging both sides to exercise "maximum restraint" and take all necessary steps to reduce tensions and avoid further conflict.

Thailand is the more economically and politically powerful of the two, so it likely hopes to avoid seeking outside opinions that could force it to lose ground. Thai government spokesman Panitan Wattanayagorn ruled out foreign involvement again Monday.

Each side blames the other for instigating each day's clashes, which have shattered a series of cease-fire agreements.

Cambodian officials say a Thai artillery barrage Sunday collapsed part of "a wing" at the Preah Vihear temple, but Thai officials have dismissed that account as propaganda. The extent of damage was unknown because it remained too dangerous to approach the temple, Cambodian authorities said.

U.N. Secretary-General Ban Ki-moon said he was "deeply concerned" by the fighting and urged both sides "to exercise maximum restraint," his spokesman said in a statement.

Built between the 9th and 11th centuries, Preah Vihear (pronounced pray-AH vih-HEER in Cambodia and prah WEE-hahn in Thailand) is dedicated to the Hindu diety Shiva.

It is revered partly for having one of the most stunning locations of all the temples constructed during the Khmer empire — the most famous of which is Angkor Wat. It sits atop a 1,720-foot (525-meter) cliff in the Dangrek Mountains about 150 miles (240 kilometers) north of the Cambodian capital.

At least seven people have died in the border clashes that began Friday — one civilian and one soldier from Thailand, where 25 soldiers have been wounded. Cambodia's foreign ministry said five Cambodians have been killed, including at least two soldiers, and 45 people wounded.


Associated Press writers Thanyarat Doksone, Todd Pitman and Jocelyn Gecker in Bangkok contributed to this report.