Mexico City, (Agencies): The leader of a gang became the first woman in the country to be sentenced to life imprisonment for carrying out kidnappings in Mexico's northern state of Chihuahua.

According to the state government, Erika Patricia Alonso Sandoval, 28, was found guilty in the abduction and subsequent murder of two businessmen.

Another member of the Los Mochadedos - or the finger-choppers gang - 18-year-old Alfredo Cruz Guzman, was jailed to life in prison in December.

Chihuahua prosecutors suspect Los Mochadedos in six other kidnappings.

The gang fell apart in November after a raid on a house where a 43-year-old businessman was being held captive. The kidnappers had already cut off several of the captive's fingers to pressurise his family into paying a ransom of five million pesos ($415,000).

The raid also led to the discovery of a second Los Mochadedos safe house, where the agents detained Alonso, Cruz Guzman and two minors.

Chihuahua authorities, federal police and the army have detained 49 suspected kidnappers belonging to 10 different criminal outfits.

The state, which borders Texas in the US, accounted for 32 percent of the more than 15,000 criminal world murders reported last year in Mexico.