A Thai army drone blitzed a Cambodian home as border clashes escalated.

Video shows the combat drone targeting a rural house near the Chong Chom crossing in Thailand's Surin province, on December 8.

The strike flattened the rural residence as Thai troops also bombed a casino and signal jammers along the disputed border.

Both nations traded blame for triggering the renewed fighting that erupted on Monday.

The Thai military said four soldiers were killed and 68 were wounded, while the Cambodian defence ministry said nine civilians were killed and 20 were injured since the skirmishes resumed.

Thailand and Cambodia have been fighting for more than a century over several undemarcated sections of their 817-kilometre (508-mile) border, which was originally mapped by France in 1907 while Cambodia was still its protectorate.

But tensions flared in the long-disputed frontier as both accused each other of instigating violence on July 24, which killed at least 48 and temporarily displaced some 300,000 on both sides of the border.

Cambodia claimed responsibility for the alleged war crime of firing rockets into Thailand that struck a gas station, killing a number of children.

The two nations have reached a shaky truce following talks facilitated by Malaysian Prime Minister Anwar Ibrahim, chair of the Association of Southeast Asian Nations (ASEAN).

But the peace deal, brokered by US President Donald Trump, fell through as Thailand accused Cambodia of laying fresh landmines that have maimed soldiers along the disputed frontier.