The landmine that injured three rangers of the Suranaree Taskforce near the Cambodian border in Surin province on Tuesday did not belong to the Thai army, Gen Prayuth Chan-ocha said on Friday.
File Photo by Busaba Sivasomboon
One mine was triggered by a Thai soldier, and 11 others were later found closeby.
"We will check who planted the landmines there, but we did not put them there. Someone else did," the national army chief said.
"I ask soldiers along the border to exercise caution and I feel for them because being a soldier means you have to risk your life."
Gen Prayuth said he had instructed the 2nd Army Region, which oversees the Suranaree Taskforce, to look into the issue and send a protest note to Cambodia via the Thai Border Committee
On Thursday, Defence Minister Sukumpol Suwanatat also insisted that the landmines found at the scene of the explosion did not belong to Thailand.
The mines were planted about one metre across the border into Thai territory, ACM Sukumpol said.
Phnom Penh is still silent on the discovery of the landmines on the border.
Both countries are signatories to the Ottawa Treaty, which bans the use and stockpiling of landmines. Cambodia has suffered severely from landmines planted during the Khmer Rouge regime, and was among the leading nations pushing for the treaty.