By Nga Pham
BBC News, Hanoi
Vietnamese authorities have arrested three women and a man for allegedly smuggling newborn babies to China.
The suspects were detained with two baby boys, aged one month and one week old, in Hanoi and Ha Tay provinces.
Hanoi police said they had also detained an eight-month pregnant woman who confessed to agreeing to sell her unborn baby to the gang.
The woman was being transferred to China, where she is expected to give birth to the child.
All the babies were sold for eight million dong ($500) each.
The police said they would be offered for adoption to couples in China for around $2,000 each, because they were boys.
Girls would be sold for half the amount, according to investigators.
This is the first time the Vietnamese police have uncovered the smuggling of unborn babies.
One of the boys has been returned to his birth mother, while the other is being looked after at a children's hospital in Hanoi.