Thai army tanks travel on a road near the Thai-Cambodia border in Surin province April 28, 2011. [Photo/Agencies]

PHNOM PENH - Gunfire exchanges between Cambodian and Thai troops over the border area at the Ta Moan temple and Ta Krabei temple in Oddar Meanchey province broke out again Thursday morning, said a field military commander.

"The fighting started again this early morning around 3:50 am at the two temples, Thai soldiers triggered the attack first," Suos Sothea, deputy commander of the artillery unit, told Xinhua by telephone from the battle fields.

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"In fact, Thai troops have fired artillery shelling on our troops almost throughout tonight and they have increased shelling in early Thursday morning," he said.

"Thai forces have fired both small guns and heavy artilleries on our troops over the areas, they have ambitions to fight and capture the temples," he said. "We have also exchanged some small guns to defend our territory, we do not use heavy guns to fight back yet," he said.

The fighting marks the seven straight days of armed clashes between the two countries' troops. No immediate casualties are available for Thursday fighting.

The last six days of clashes has killed eight Cambodian and five Thai soldiers, and one Thai civilian.

The border between Thailand and Cambodia has never been completely demarcated. Cambodia's Preah Vihear temple was enlisted as a World Heritage Site on July 7, 2008. But Thailand claims the ownership of 4.6 square kilometers (1.8 square miles) of scrub next to the temple. Just a week after the enlistment, Cambodia and Thailand had a border conflict, triggering a military build-up along the border, and periodic clashes between Cambodian and Thai soldiers have resulted in the deaths of troops on both sides.