Nguyen Thi Ngoc Diep, 34, and Tran Thi Dal, 32, are being investigated for "human trafficking", a crime punishable by up to 20 years in prison.

Police said both women were promised $2,000 each besides travel expenses by a Chinese man who had hired them to smuggle the boys to Pingxiang City in China.

Earlier this month, Diep and Dal had collected the two minors near the Vietnam-Cambodia border, seeking to buy fake birth certificates via social media before flying to Hanoi.

They had then moved to Cao Bang Province, 280 kilometers northeast of Hanoi, and hired an unidentified man to take them to the Chinese border. However, the women lost contact with the driver and took a taxi back to Lang Son Province where they were discovered acting suspiciously by police.

In custody, the women admitted they were trying to smuggle the boys to China.

The minors are now in stable condition and receiving care at a local social protection center.

Police are expanding their investigation.

Vietnam recorded over 3,400 cases of human trafficking between 2013 and 2019, with over 90 percent of the victims being women, children and ethnic minority members, according to the Ministry of Labor, Invalids and Social Affairs.