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

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 army’s statement said the incident took place in Thailand’s Sisaket province and “clearly demonstrates to both domestic and international society that the use of concealed weapons in border areas continues to exist,

The Thai army will continue to detain 18 captured Cambodian soldiers as long as Phnom Penh continues to break the agreed-on bilateral ceasefire and to use landmines, spokesman Maj Gen Winthai Suvaree said on Monday.