At least 13 Cambodians were killed and 71 injured in ongoing border clashes with Thai forces, Cambodian officials confirmed Saturday. The fighting, now in its third day, reportedly began when Cambodian troops opened fire near Thailand’s Trat province, according to Xinhua.

Five Cambodian soldiers and eight civilians were killed, with most casualties in Oddar Meanchey province. Thailand responded with a military operation, “Trat Strike 1,” pushing back Cambodian forces at multiple points and deploying naval support.

The conflict has since spread to Cambodia’s Pursat province, as tensions along the border continue to rise, Xinhua reported.