Thai authorities allowed approximately 20,000 Cambodians to cross the border through a checkpoint in Pong Nam Ron district, Chanthaburi, on Sunday.
Thousands of Cambodians had gathered from early morning at the Ban Laem border checkpoint in Tambon Thep Nimit, waiting to return home.
In response, the Chanthaburi-Trat Border Defence Command opened the border gate on humanitarian grounds to facilitate their return.
Immigration police, tourist police, military personnel, and district officials collaborated to manage the large crowd and expedite immigration procedures.
Thai officials estimated that between 17,000 and 20,000 Cambodians successfully crossed the border on Sunday.
Authorities also expect another wave of Cambodian nationals to cross via the same checkpoint on Monday.