Mexican authorities on Monday said they had nabbed an alleged lieutenant and bodyguard of Joaquin "Chapo" Guzman, the billionaire boss of the Sinaloa drug cartel.

Authorities said the arrest of Felipe Cabrera, a man with a reputation for violence who is known by the nicknames "College Grad" and "Lord of the Mountain Range," should deal a serious blow to the cartel.

Cabrera -- who was arrested in Culiacan, the capital of Sinaloa state -- was presented to local media in Mexico City on Monday.

Army spokesman Ricardo Trevilla described Cabrera as a Guzman lieutenant in Durango state and part of Chihuahua state, both in northern Mexico, who "was in charge of personal security for ... Guzman" in that area.

Cabrera is believed to be behind secret burials of murder victims, kidnapping, extortion and arson attacks on businesses and homes, authorities say.

More than 45,000 people have been killed in drug-related violence in Mexico since December 2006, when the government of President Felipe Calderon launched a military-led crackdown on the cartels.

Guzman -- the most wanted drug boss in Mexico and the United States -- was named earlier this year by Forbes magazine as one of the world's most powerful people after 10 years on the run.

Born to peasants in Mexico's legendary northwest drug trafficking state of Sinaloa, Guzman made the Forbes list of the world's billionaires in 2010, with a fortune of more than $1 billion.

Elsewhere, Mexican troops made a grisly Christmas discovery when they found 13 bodies in a truck in the northeastern state of Tamaulipas, authorities said in a statement.

Investigators say the murders are linked to Friday's discovery of 10 bodies in the town of Tampico Alto, in neighboring Veracruz state, and attacks by gunmen last week on three buses that left 16 people dead.

Two months ago, the government sent police and army reinforcements into Veracruz after an escalation in killings attributed to the bloody feud between the Sinaloa cartel and the rival Zetas.