Mexico's governmental human rights agency says municipal police were complicit in at least 38 abductions and killings in the town of Allende in northern Coahuila state, near the U.S. border.

The National Human Rights Commission issued a recommendation Monday calling on authorities to make amends to the victims' families and ensure they could return to Allende.

The commission said the Zetas drug cartel carried out the killings "with the authorization, support or acquiescence" of local police.

From March 18-20 of 2011, the Zetas sent gunmen and local police to round up everyone who shared a certain last name in the town. They were punishing someone they believed had betrayed them.

The precise number of people who disappeared is unknown, but estimates vary from a few dozen to several hundred.