The Mexican Red Cross condemned the killing of an off-duty volunteer over the weekend in the northern state of Nuevo Leon.

Federico Suarez Tamez and one of his sons were taken from their residence by several gunmen.

The victims' bodies were found Saturday near a federal highway close to the city of Montemorelos.

"There is no reason or justification whatsoever for taking the life of Mexican Red Cross personnel," the humanitarian organization said.

The 50-year-old Suarez Tamez served as a radio operator for the Red Cross in Allende, a town in Nuevo Leon.

Investigators suspect that the Red Cross volunteer and his son were killed by members of an organized crime group.

"This sad incident occurred outside his activities as a rescuer, when he was at home without a uniform on," the Red Cross said.

Suarez Tamez "always showed that he was a person committed to the emergency and humanitarian work done by the institution with the sole objective of saving lives," the Red Cross said.

The volunteer "had earned the respect and recognition of his colleagues," the humanitarian organization said.

"The work done by Mexican Red Cross volunteers ... has been characterized by unselfishness, putting their own lives in danger in the course of rescuing people who are in danger in an emergency," the Red Cross said.

Mexican "society should respect the work done by volunteers, but above all ... their physical integrity, since their work is solely to relieve the suffering of people without regard to race, political beliefs, religion, economic or religious situation," the humanitarian organization said.

Montemorelos has been the scene in recent months of several violent incidents.

Ten people have been found dismembered this year in the city and six others were reported missing.

Los Zetas, considered Mexico's most violent drug cartel, and the Gulf cartel have been fighting for control of the area.