BANGKOK (AP) — Thailand launched airstrikes along the disputed border with Cambodia on Monday as both sides accused the other of attacking first.

Tensions have simmered since the Southeast Asian neighbors signed a truce agreement in October pushed by U.S. President Donald Trump after their territorial disputes led to five days of combat in July that killed dozens of soldiers and civilians.

Thai army spokesperson Maj. Gen. Winthai Suvaree said the Cambodian troops fired first into Thai territory in multiple areas. He said one Thai soldier was killed and four other soldiers were wounded, and civilians were being evacuated from the affected areas.

Thailand used aircraft “to strike military targets in several areas to suppress Cambodian supporting fire attacks," he said.

Cambodian Defense Ministry spokesperson Maly Socheata said the Thai military attacked the Cambodian troops first. She said Cambodia did not retaliate during the initial attacks Monday.

“Cambodia urges that Thailand immediately stop all hostile activities that threaten peace and stability in the region,” she said.

The U.S.-brokered ceasefire that ended the brief conflict was threatened last month after Thai troops were injured by land mines. Both sides continue to trade accusations over responsibility, even as they are supposed to be cooperating in getting rid of the mines.

Trump said in mid-November he'd stopped a war between them as the tensions simmered.