A landmine blast on Saturday wounded three Thai soldiers on patrol near the border with Cambodia, days after the two sides agreed a ceasefire to end their deadliest military clashes in decades.

The blast occurred in Sisaket province at around 10:00 am (0300 GMT), the Royal Thai Military said in a statement.

One soldier suffered a severe leg injury, another was wounded in the back and arm, and the third had extreme pressure damage to the ear.

The incident came after at least 43 people were killed in a five-day conflict that ended on July 29 following a long-running dispute over border temples.

The clashes -- involving jets, artillery, rockets and infantry battles -- ended with a ceasefire, after cajoling by US President Donald Trump. 

A meeting of defence officials in Kuala Lumpur ended on Thursday with a deal to extend the ceasefire.

Thailand's acting Prime Minister Phumtham Wechayachai was in neighbouring Surin province on Saturday and has ordered the military to ensure the wounded soldiers receive full medical treatment.

Last month's clashes along the 800-kilometre (500-mile) border forced more than 300,000 people to flee combat areas on both sides of the border.