The Mexican government charged 73 suspects Wednesday in the killings of 183 people whose bodies were recovered during April in mass graves near the U.S. border, prosecutors said.
The defendants were booked in different jails in Mexico while waiting to see a federal judge, said Ricardo Najera, spokesman for federal Attorney General's Office.
The government had in the past weeks announced the detention of 74 people, including several police officers who allegedly protected gang members, but Najera said no one had been charged until Wednesday. He said more suspects were in custody of the federal government pending charges, but he didn't know the number.
It wasn't clear which specific crimes the 73 suspects were charged with, but officials said they were related to the grisly discovery of 183 corpses in San Fernando, a town 85 miles (137 kilometers) from the border at Brownsville, Texas.
The excavations in the border state of Tamaulipas shocked Mexicans around the country, who filed dozens of missing-person reports as the horrifying tale of the mass graves unfolded.
Federal officials said most of the victims were Mexicans looking to migrate to the United States in March, but who instead were kidnapped off passenger buses and killed. The government has identified only 12 victims so far _ one a Guatemalan man, the rest Mexican.
Authorities blamed the Zetas gang, a vicious drug-trafficking organization suspected of forcefully recruiting migrants to fight the formerly allied Gulf cartel. Those who refused are killed.
Mass graves are a common method used by Mexican drug cartels to bury their victims.
In the northern state of Durango, authorities have unearthed 226 bodies since April 11 in residential neighborhoods in the state capital, also called Durango. The latest three bodies were removed this week, Fernando Rios, spokesman for the state police, said Wednesday. Excavations continue.
The mass cases in Tamaulipas and Durango don't appear to be connected, officials have said.
A top federal police official who spoke on the condition of anonymity said recently that the killings in Durango stem from an internal bloody battle for power within the same gang _ the Sinaloa drug cartel.
Durango borders the state of Sinaloa, the cartel's home base, and the gang keeps a strong presence in the vast region close to the Sierra Madre Mountains.
In another drug-related incident in the Sinaloa state capital, Culiacan, the Mexican army said Wednesday that soldiers found $500,000 in cash inside a sport utility vehicle that a drug suspect abandoned alongside a highway.