A Mexican judge has ordered 16 police officers and three drug dealers in Tarandacuao, a city in the central state of Guanajuato, prosecuted for allegedly working with the La Familia Michoacana cartel, the Attorney General's Office said.

The prosecutions were ordered as a result of an investigation into the killings of three people in February and April, the AG's office said.

A message claiming that the killings had been carried out by La Familia Michoacana was left with two of the victims, the AG's office said.

La Familia Michoacana, which operates in Michoacan, the southern state of Guerrero and the central state of Mexico, which surrounds the Federal District and forms part of the Mexico City metropolitan area, is considered the largest trafficker of synthetic drugs in Mexico.

The criminal organization is one of the federal government's main targets, with security forces stepping up their operations against the criminal organization since the discovery on July 13, 2009, of the bodies of 12 Federal Police officers.

The killings were apparently a reprisal for the arrest two days earlier of Arnoldo Rueda Medina, a major La Familia figure.

The deputy police chief of Tarandacuao, 16 officers and three drug dealers were arrested on April 29, federal prosecutors said.

The police officers worked for the drug cartel, staging kidnappings, carrying out contract hits and committing other crimes, the AG's office said.

The suspects were turned over to federal authorities on May 1 and a federal judge approved their prosecution on drug, criminal conspiracy and other charges.

No information has been provided, however, about the status of the case against the deputy police chief.

Last week, 130 police officers in Acambaro, another city in Guanajuato, were arrested by the Federal Police for allegedly having ties to drug traffickers.

Guanajuato state police officers, backed by helicopters, took control on May 3 of the city, located in the southern part of the state, near the border with Michoacan state.

Guanajuato is governed by the conservative National Action Party, or PAN, while Acambaro's city hall, under Mayor Gerardo Silva Campos, is in the hands of the leftist Party of the Democratic Revolution, or PRD.