The Mexican Public Safety Secretariat said federal police freed 27 Mexicans, 14 Guatemalans, six Chinese, two Hondurans and two Salvadorans Monday, Fox News Latino reported.
The rescue operation was the second in the border town near McAllen, Texas, in less than a week. Fifty-six Mexicans and a dozen foreigners were freed in Reynosa last Wednesday, Fox said.
Reynosa is about 90 miles north of San Fernando, where authorities recently discovered 177 bodies in mass graves. Another 72 bodies were found there last year.
The BBC reported Mexico's National Human Rights Commission says more than 11,000 migrants were abducted over a six-month period last year, many of them kidnapped by criminal gangs that hold them for ransom or force them to work for drug cartels.
About 35,000 people have died in drug-related violence in Mexico since late 2006.