China has dismissed allegations that it was supplying weapons to Cambodia amid its ongoing border conflict with Thailand that has led to at least 33 people dying and hundreds of thousands displaced.

The deadly conflict on the Thai-Cambodian border pits a longtime United States ally with decades of experience against a relatively young armed force with close ties to China.

Thailand warned its conflict with neighboring Cambodia could “potentially develop into a war” as troops used rockets and artillery to shell targets along their contested border for a second day.