The head of the Association of South East Asian Nations called on Thailand and Cambodia to cease fighting and negotiate a settlement to their border dispute.

ASEAN Secretary-General Surin Pitsuwan, who is also a former foreign minister of Thailand, added his voice to that of U.N. Secretary-General Ban Ki-moon in an appeal for both countries to show restraint and stop fighting that claimed four lives last weekend.

"The world and ASEAN have been alarmed by the new outbreak of violent and fatal clashes along the Cambodian-Thai border," he said.

"I can only add my voice to that call for a peaceful solution to a long simmering tension between our two ASEAN member states. There is really no other alternative to a genuine dialogue between the two sides."

The latest flare up began Friday when both sides accused the other of firing first, with Cambodians also accusing Thai troops of using cluster bombs. At least 10 soldiers have been killed and dozens wounded in the area around the 11th-century Preah Vihear temple.

The disputed land -- less than 2 square miles -- contains the temple, a World Heritage Site in the Dangrek Mountains 300 miles east of Bangkok on Cambodia's northern border.

The International Court of Justice ruled in 1962 that the temple was on Cambodian land but the some access to the mountaintop structure passes through the Thai side, a route that Thai troops occasionally seal off.

Cambodia managed to get the temple listed as a World Heritage Site in 2008, much to the annoyance of Bangkok.

Around 2,000 troops from both sides are stationed across from each other on border patrol. Cross-border incidents occasionally flare up, such as in October 2008 when two Cambodian troops died and seven Thai troops were wounded in a gun battle lasting an hour.

After the first fighting in February, Ban said he was "deeply concerned" about the latest skirmishes and called on both sides to "exercise maximum restraint."

The renewed fighting is a major disappointment to ASEAN whose chair country, Indonesia, convened a special meeting Feb. 14 in Jakarta of ASEAN foreign ministers who worked out a cease-fire that had been adhered to until last week.

"We thought we had responded effectively to the call of the U.N. Security Council's with our own ASEAN's approach to the problem of our two member states," said Pitsuwan. "The renewed fighting not only disappointed the other ASEAN member states, we have also failed the world in its expectation of all of us."

Marty Natalegawa, foreign minister of Indonesia and chairman of ASEAN, will meet with the Thai and Cambodian foreign ministers today to discuss a ceasefire and possibly unarmed military observers.

In the last major meeting of ASEAN to discuss the border dispute in February, Thailand and Cambodia initially agreed to allow unarmed military observers from Indonesia to be posted in the disputed area.

But Thailand changed its minds and the observers weren't installed.

Last weekend, Thai Prime Minister Abhisit Vejjajiva reiterated his belief that observers were not needed, but talks with Cambodia are essential for a bilateral agreement.

"We must not fall into Cambodia's trap in trying to spread a picture of conflict or say the conflict is unsolvable through bilateral talks," he said in a televised speech. "We will definitely not let that happen."