Col Prawit said the injured soldier was identified as Sgt Chatree Kaewprasan. He was sent to hospital in Ubon Ratchathani and is now recovering.
Sgt Chatree lost his right leg while leading his patrol to search for illegal loggers along the border in Si Sa Ket's Kantararak district Wednesday night.
The spokesman said the landmines were recently planted by illegal loggers in two spots located in Thai territory.
The authorities believe that the loggers wanted revenge after Thai troops launched a crackdown to prevent the gangs from falling rosewood trees, according to army spokesman.
Col Prawit also reaffirmed that the situation along the Thai-Cambodian border remains normal with troops of both sides being deployed in the area and having good relationship.
Early this week, Cambodia accused that its troops on patrol were attacked by Thai soldiers, but the Thai army spokesman Col Sansern Kaewkamnerd dismissed the claim.
He said Sunday’s border skirmish occurred as Thai paramilitary rangers and forestry department workers on patrol to prevent contraband logging fired warning shots when they saw logging poachers falling rosewood trees in Thai territory half a kilometre from the border.