Three Thai soldiers were injured by a landmine near the Cambodian border on Saturday, the Thai army said, days after the Southeast Asian neighbours agreed to a detailed ceasefirehalting last month's deadly five-day conflict, Reuters reported.

One soldier lost a foot and two were injured after one of them stepped on a landmine while patrolling an area between Thailand's Sisaket and Cambodia's Preah Vihear provinces, the army said in a statement

The soldiers were being treated at a hospital, it said.

Thailand said the incident occurred in an area of its territory recently cleared of landmines. The foreign ministry said Bangkok would lodge a complaint against Cambodia for violating a treaty, to which both are signatories, that bans the use of landmines and for infringing Thai sovereignty, according to Reuters.