Clashes involving artillery on the Cambodian-Thailand border have continued for a second day in a row, Cambodian Ministry of National Defense spokesperson, Lieutenant General Mali Socheata said Friday.

“Both armies continued to use heavy artillery to shell each other’s positions. Our troops are firmly in control of their positions along the entire front line and are fearlessly firing at the aggressive enemy,” the Cambodian defense ministry spox said.

According to her, the Thai military on Thursday struck eight targets in Cambodia using heavy weapons and F-16 fighter jets. Socheata had previously said that the Cambodian army was acting solely in self-defense, responding to an “unprovoked incursion” by Thai troops that had “violated Cambodia’s territorial integrity.”

As border clashes between Cambodian and Thai forces have escalated, residents of border areas between the two countries have been forced to evacuate to safer areas. Authorities in Cambodia’s Preah Vihear province said more than 20,000 residents had been evacuated to safer areas. And Thai authorities said more than 100,000 residents in border areas had fled their homes.

Relations between Cambodia and Thailand have continued to deteriorate since an armed incident on May 28. That day, Thai soldiers opened fire on a Cambodian military position located in the disputed territory between the Cambodian province of Preah Vihear and the Thai province of Ubon Ratchathani, in Techo Morakot village in Choam Ksan District. One Cambodian soldier was killed and several others were injured in the incident.