MONTERREY, Mexico – The Nuevo Leon State Investigations Agency, or AEI, commander in San Pedro, a town in northern Mexico, was killed by gunmen, officials said.

Maj. Antonio Montiel Alvarez was gunned down around 10:30 p.m. Friday on a road in Benito Juarez, a city on the east side of the Monterrey metropolitan area, Nuevo Leon state Security Council spokesman Jorge Domene said.

“Maj. Montiel was resting with his family at that place when he was attacked by a group of armed men,” Domene said.

Montiel fought back and was murdered, “but his family was not harmed,” Domene said.

There are reports that the state police officer may have been killed by an organized crime group, the state Security Council spokesman said.

Threats against AEI members have increased in the past few months as the drug-related violence has surged across Nuevo Leon, Domene said.

A total of 324 murders were registered in Nuevo Leon in the first two months of the year, a record for a two-month period in the state, Domene said.

“From 2009 to now, the number of murders has been rising from month to month,” the state Security Council spokesman said.

Common crimes, such as burglaries, auto theft and hold-ups, have been falling since August, Domene said.

The wave of drug-related violence in Nuevo Leon claimed the lives of 2,003 people in 2011, official figures show.

Los Zetas has been battling the Gulf cartel for control of the Monterrey metropolitan area and smuggling routes into the United States.

Heriberto Lazcano Lazcano, known as “El Lazca,” deserted from the Mexican army in 1999 and formed Los Zetas with three other soldiers, all members of an elite special operations unit, becoming the armed wing of the Gulf drug cartel.

After several years on the payroll of the Gulf cartel, Los Zetas, considered Mexico’s most violent criminal organization, went into the drug business on their own account and now control several lucrative territories.

Mexico’s drug war death toll stood at 47,515 from December 2006 to Sept. 30.

The murder total has grown every year of President Felipe Calderon’s military offensive against the well-funded, heavily armed drug cartels.

Unofficial tallies published in December by independent daily La Jornada put the death toll from Mexico’s drug war at more than 50,000.