Saturday’s incident is the third time in a few weeks that Thai soldiers have been injured by mines while patrolling along the border.

Thailand’s army said three soldiers were injured in a landmine blast near its disputed border with Cambodia, threatening a fragile ceasefire agreement between the two neighbors.

Yet up until the recent outbreak that began in late May and ended with a cease-fire on July 28, the two countries were still able to manage bilateral military cooperation after the last of the Khmer Rouge insurgency in Cambodia was defeated in 1998.