Police in northern Mexico have arrested two people accused of buying Mexican babies to sell to U.S. couples.

Officials say Amado Torres and his wife Maria Isabel Hernandez are believed to have bought more than a dozen children aged 2 or younger.

Investigator Oralia Mancha says the child-trafficking ring came to light when the grandmother of one of the babies reported the child missing Monday in Reynosa. While making the declaration, she spotted Torres in the police station and claimed he had the baby.

Police later arrested Torres and Hernandez after finding them with the baby at a house in nearby Rio Bravo.

The baby's mother was also taken into custody on selling her newborn for $3,000.