Nationalist Thais protested in front of the Cambodian Embassy amid a territorial dispute along the border with their neighbour.

Footage shows rallyists waving Thai flags outside the diplomatic building in Bangkok on June 6 as they called on army chiefs to 'protect Thai territory', which was once part of the mighty Khmer empire.

They blared impassioned speeches through a sound truck in front of the heavily guarded Cambodian Embassy barricaded with fences and surrounded by dozens of police officers.

Protest leader Nasser Yima of the Student and People's Network for Thailand Reform said: 'The disputed area belongs to Thailand, not Cambodia, and Cambodia cannot claim ownership of it. Thai people love their country and will not allow Cambodia to seize land that belongs to Thailand.'

Another protester, Phichit Chaimongkol, said: ‘Currently, the government does not even dare to warn Cambodian soldiers about their actions of invading Thai territory. When the Thai government is afraid to protest or warn them, we have to rally on behalf of the government today.

‘Cambodia's actions are intentional and meant to cause conflict between the two countries. Thai people are ready to support the military's operations and will not give up even an inch of land.'

Tensions between Thailand and Cambodia have intensified following a deadly clash between their troops in a disputed area of Ubon Ratchathani, on May 28.

The skirmish killed a Cambodian sergeant. Thailand said it was committed to resolving the dispute conflict through bilateral means, while Cambodia has vowed to bring the case before the International Court of Justice in The Hague.

Thailand and Cambodia have a fractious history. The Khmer Empire once stretched across much of Southeast Asia before the ancient leaders moved their base south to Phnom Penh in the 16th century amid water shortages.

Thai tribes used it as a chance to encroach and claim much of the deserted land, including priceless sandstone temples and artefacts.

In the 1970s, Thailand supported the Khmer Rouge while they carried out one of the world's worst ever genocides. The country then provided sanctuary for the group's murderous leaders, even stealing aid funds from the West that were intended to rebuild Cambodia.