Mexican authorities say a hit squad of two teenage girls, a boy and a woman has been detained for allegedly killing three boys aged 13, 14 and 15 in a poor neighborhood of northern Mexico.

A police official in the northern state of Tamaulipas says the killings in the state capital of Ciudad Victoria appeared related to a dispute over control of street-level drug dealing. The official was not authorized to be quoted by name.

The youthful hit squad was travelling in a van and shot their victims on the street. A 17-year-old survived the shooting and was in serious condition at a hospital.

In 2010, a 14-year-old U.S. citizen confessed to killing four people in Mexico whose beheaded bodies were found hanging from a bridge.