High-ranking drug cartel member Arnoldo Rueda Medina was arrested Saturday, triggering an ambush on police.

In the latest incident, 12 bodies of federal police officers were found on the side of a remote highway, said Monte Alejandro Rubido Garcia, technical secretary for Mexico’s national security council, at a news conference Tuesday. The bodies showed evidence of torture.

The officers were “ambushed while they were off duty by an armed group,” Rubido said. One of the 12 officers was a woman.

The bodies were found in a pile near the town of La Huacana, he added.

Rubido said the slain officers had been doing “investigative work” in the city of Arteaga in Michoacan, one of the states most affected by the government’s offensive against drug cartels.

Rubido announced the arrest of Francisco Javier Frias Lara, known as “El Chivo,” in connection with the killings of the officers.

Frias is a member of La Familia Michoacana, one of the region’s most powerful drug cartels, Rubido said.

Federal police around the country will redouble security measures for its agents, Rubido said.

The sudden spike in violence followed the arrest Saturday of Arnoldo Rueda Medina, who authorities described as a high-ranking member of La Familia Michoacana.

Cartel members first attacked the federal police station in Morelia to try to gain freedom for Rueda, authorities said. When that failed, the drug gangs attacked police installations in at least a half-dozen Michoacan cities. Coordinated attacks in eight cities over the weekend left three federal police officers and two soldiers dead.

It was the federal police who arrested Rueda, and the current spate of attacks appear aimed at them in revenge.

On Tuesday, two federal police officers were killed and four wounded in an ambush in Michoacan, the state-run Notimex news agency reported.

Also Tuesday, a federal police station in the Michoacan city of Maravatio was attacked, news reports said. There were no immediate reports of casualties.

A local Michoacan newspaper put the body count in recent days at 32.

La Familia Michoacana emerged in the 1990s as a conservative paramilitary group designed to insulate the state from the large drug cartels, said Bruce Bagley, a professor at the University of Miami and expert on drug trafficking.

But over the years, the group evolved into a drug trafficking operation itself, forging strategic alliances with warring cartels to raise its own profile.

This week’s violence solidifies the cartel as a major and violent player in Mexico’s drug wars, Bagley said.

“This represents the third evolution of the Familia Michoacana,” he said.

Reprisals from drug cartels following major arrests have been reported before, but the intensity of these attacks in Michoacan are unprecedented.

La Familia Michoacana wants “to demonstrate that they have power and will not go away quietly into the night,” Bagley said.

Initial reports indicated that 11 men and one woman were likely killed elsewhere at least a day earlier and dumped near the town of La Huacana, officials in the state attorney general’s office said.

It was one of the largest execution-style slayings since the killing of 24 men whose bodies were found bound with duct tape and shot in the head in September in a rural area west of Mexico City. In August 2008, the decapitated bodies of 12 men were found outside the southern city of Merida.

The officials, who spoke on customary condition of anonymity, said the number of victims could increase as police continue investigating the scene.

Also in Michoacan on Monday, the bodies of two men who had been tortured and executed were found near an airport in the state capital, Morelia.

In both cases, the methods used by the killers were those often used by drug cartels to eliminate rival traffickers.

In the Michoacan port of Lazaro Cardenas on Monday, gunmen attacked a hotel where federal police stay, wounding at least one officer, the officials said.

The attacks were in retribution for the capture early Saturday of Arnoldo Rueda Medina, a high-ranking member of the drug gang known as La Familia Michoacana (The Michoacan Family), the state-run Notimex news agency reported.

Medina is known as chief of assassins within the organization and a close confidante of Nazario “El Chayo” Moreno, one of the group’s two top leaders, the Mexican newspaper El Universal reported Saturday.

Men armed with high-powered rifles and grenades launched the attacks in the cities of Morelia, Zitacuaro, Zamora, Lazaro Cardenas, Apatzingan, La Piedad and Huetamo in Michoacan state, Notimex news said, citing federal police authorities.

The three officers were killed in Zitacuaro, police official Eduardo Moran told CNN en Español, while six police officers were reported wounded in Morelia. Two soldiers were killed in Zamora, shot by men in a passing car as they walked to their headquarters.

The threat was made in a note found on the windshield of a slain officer’s car, news reports said.

At least three Tijuana officers have been killed since Monday, reports said. Leyzaola, a former army colonel, replaced a police chief removed from office in December after receiving numerous threats.

“Leyzaola has become the poster boy for honest police work, which has put the drug gangs on notice,” Vicente Calderon, a reporter for the Tijuana Press news agency, told CNN affiliate KUSI.

“They believe he is serious, that he means business and is trying to re-establish the rule of law that has been affecting the city and whole state for many years since organized crime established themselves in Baja [California].”