Ignoring Thailand's protest, Cambodia on Thursday took military attaches from 12 countries to visit Preah Vihear temple and the 4.6 square kilometre disputed area.
Thai soldiers could not do anything but make another protest, a military source said.
The source said the military attaches from the United States, France, Russia, China, Japan, Australia, Singapore, New Zealand, Malaysia, Burma, Vietnam and Laos were taken from Phnom Penh to the temple ruins about noon.
"The Suranaree Task Foce sent another protest to Cambodia. Cambodia violated an agreement by taking a group of people to the disputed area without Thailand's consent," the source said.
Cambodia's intention was to let the attaches see damage it claimed was caused by Thai shelling in the cross-border fire from Feb 4-7.
"We could not do anything else but lodge a protest. We are ordered not to fire, because doing that will only cause tension and allow Cambodia to make publicity out of it.
"This indicates that Cambodia has no fear at all, even though Thai soldiers have been deployed along the border," the source said.
The visit followed a visit by military attaches to the Thai side of the border on Feb 21, organised by the Defence Ministry. They did not enter the disputed area.