PHNOM PENH - Cambodia has protested alleged Thai military earthworks near Boundary Pillar No. 9 in Oddar Meanchey province.

Cambodia’s Foreign Ministry said Thai forces used heavy machinery on Sept. 15 to level ground and build an earthen trench near the pillar in the Ta Tum area of Anlong Veng district. Phnom Penh described the reported activity as a violation of Cambodian sovereignty. AKP reported the protest.

Cambodia bases its claim to the area on historical boundary maps produced under agreements between France and Siam in the early 1900s. Parts of the Cambodia-Thailand boundary remain disputed and subject to bilateral survey and demarcation.

Cambodia also said the alleged earthworks breached a 2000 border-demarcation memorandum and a Dec. 27 joint statement. 

The memorandum restricts work that changes the frontier-zone environment, while the December statement calls for survey and demarcation through the Joint Boundary Commission and says neither side should construct or enhance military fortifications beyond its own side.

Thailand has previously said border disputes should be resolved peacefully through bilateral mechanisms, including the JBC.

Cambodia made a similar protest in July, alleging Thai road construction between Boundary Pillars 8 and 9 in the same Ta Tum area.

In its latest statement, Cambodia demanded that Thailand stop the reported activity near Pillar No. 9.