Three Thai soldiers were injured by a landmine while patrolling the border with Cambodia, the Thai army said on Saturday, days after the two neighbours agreed to a detailed ceasefire following a violent five-day conflict last month.

One soldier lost a foot and two others were injured after one of them stepped on a landmine as they patrolled an area between Thailand's Sisaket and Cambodia's Preah Vihear provinces on Saturday morning, the Thai army said.

The soldiers are being treated at a hospital, the army said.

The incident is the third time in a few weeks that Thai soldiers have been injured by mines while patrolling along the border. Two previous similar incidents led to the downgrading of diplomatic relations and triggered five days of violent clashes.

The southeast Asian neighbours were engaged in deadly border clashes from July 24-28, in the worst fighting between the two in more than a decade. The exchanges of artillery fire and jet fighter sorties claimed at least 43 lives and left over 300,000 people displaced on both sides.

A fragile ceasefire has been holding since Thailand and Cambodia agreed on Thursday to allow observers from the Association of Southeast Asian Nations to inspect disputed border areas to ensure hostilities do not resume.

Bangkok accused Cambodia of planting landmines on the Thai side of the disputed border that injured soldiers on July 16 and July 23. Phnom Penh denied it had placed any new mines and said the soldiers had veered off agreed routes and triggered old landmines left from its decades of war. (Reuters)