Mexico City, Jan 9 - Children and teenagers between the ages of 11 and 17 are being recruited by Mexico's drug cartels to smuggle narcotics into the US and also work as spies, according to the US Drug Enforcement Administration and the US Immigration and Customs Enforcement.
The children are of Mexican people, other Latin Americans as well as Americans, meaning from both sides of the border.
The number of children from the US being recruited by the cartels has risen since the second half of 2011 because they enjoy the benefit of citizenship, the US departments said.
One of the places where recruiting has increased in the past few months is San Diego, California, which is near the Mexican border city of Tijuana.
The number of arrests of children has risen in southern California, with charges ranging from drug trafficking to extortion, kidnapping and piracy.
Some of the children were already working for gangs in the US and had to pass tests to show the Mexican cartels that they were reliable.
Different cartels pay the children varying amounts of money for the crimes they commit, the US departments said.
Los Zetas, considered Mexico's most violent criminal organisation, and the rival Gulf cartel pay an average of $500 to smuggle drugs, $1,000 to guard a kidnapping victim for a month and $1,500 to provide information on the movement of US authorities.
American children arrested by the US departments told investigators the money was an important motivator and they knew they would serve at most 15 months in a juvenile facility if caught.
Mexican children, for their part, are usually deported and continue working for the cartels.