Three Thai soldiers on patrol were wounded Saturday when one stepped on a land mine in territory along the border with Cambodia, Thailand’s army announced. The incident came just two days after the two countries reaffirmed their adherence to a ceasefire to end a brief armed conflict.

Thailand and Cambodia agreed to allow observers from Asean to inspect disputed border areas and prevent further hostilities.

Cambodia and Thailand agreed to maintain a ceasefire and allow neutral monitors, as the US cited a “high level of distrust” between the Southeast Asian neighbors after their deadliest border clashes in decades.