PHNOM PENH: Thai forces demolished Cambodian homes in contested border areas after a ceasefire ended clashes between the neighbours, a local rights group said on Tuesday (Jan 20).

A decades-old border dispute between the Southeast Asian nations erupted into military clashes several times last year, with fighting in December killing dozens of people and displacing around one million others on both sides.

The two countries agreed to a ceasefire in late December, ending three weeks of clashes.

Since then, Cambodia has said Thailand seized several areas in four border provinces and demanded the withdrawal of Thai troops from territory claimed by Phnom Penh.

The Thai military has denied using force to seize Cambodian territory, insisting its forces were present in areas that had always belonged to Thailand.

Rights group LICADHO on Tuesday said a "significant number of homes and structures" in Thai-controlled areas of two villages in Cambodia’s Banteay Meanchey province "have been razed and cleared by Thai forces" following the Dec 27 truce.

"The destruction of civilian homes during a conflict goes against the Geneva Conventions and international human rights law, regardless of which side of the contested border the houses stand," LICADHO said in a statement.

The demolitions had occurred in disputed areas claimed by both countries, the organisation said.

Homes were also destroyed on land recognised by both sides as Thailand, and land recognised by both sides as Cambodia, it added, citing imagery from the European Space Agency’s Sentinel-2 satellites as well as images and footage published by media outlets.

"Their clearance post-ceasefire serves no legitimate military objective," LICADHO said.

Cambodia this month condemned Thai forces for the "demolition of Cambodian civilian homes and other civilian infrastructures" in areas Phnom Penh says were seized.

Cambodia’s foreign ministry said in a statement that the actions by Thailand’s military violated international law.

A Thai foreign ministry spokesperson on Tuesday referred AFP to a Jan 12 statement from the ministry, which rejected "Cambodia’s unfounded allegation of illegal territorial annexation" on the border.

"Security measures undertaken by the Thai forces following the ceasefire are in full compliance" with the Dec 27 truce agreement, it said.

The Thai army did not immediately reply to an AFP request for comment on Tuesday.

The two nations’ border conflict stems from a dispute over the colonial-era demarcation of their 800km border, where both sides claim territory and centuries-old temple ruins.

More than 127,000 Cambodians remain in camps for displaced people following the December clashes, according to the interior ministry.