In a hair-raising standoff that sent motorists scrambling for cover, municipal police pulled their guns on masked federal agents in one of Mexico's biggest cities — a stark display of the tensions caused by a crackdown on drug corruption among the country's lawmen.
Federal forces are leading sweeps across the country to round up local officers and politicians accused of collaborating with brutal drug cartels. Many city police are furious at seeing colleagues disarmed, humiliated and dragged away in handcuffs.
The evening's confrontation started when federal police showed up to disperse city officers who were protesting the federal raids by blocking several streets in San Nicolas and Escobedo, suburbs of Monterrey, the country's third largest city.
Anxious motorists fled their cars and took cover — although no shots were fired.
"The federal officers told motorists to get out of their cars because they were afraid the city police were going to open fire," said a state police spokeswoman, who was not authorized to give her name in line with department policy.
Seven people were arrested, the state public safety department reported, but officials would not say whether they included any officers.
The incident was dramatized in photos published Tuesday by Mexican newspapers. Mexico City's Reforma showed a state officer holding his gun against the head of a federal policeman.
In Nuevo Leon state, where Monterrey is located, soldiers and federal officers this month raided police stations in 18 towns to detained 78 officers suspected of working with drug smugglers — information often gleaned from lists of police names in the possession of alleged traffickers.
Nuevo Leon state prosecutor Luis Carlos Trevino said investigators have uncovered evidence of local police kidnapping soldiers and handing them over to hit men, who then killed them.
The federal government also has arrested elected officials — including 10 mayors in Calderon's home state of Michoacan — on suspicion of collaborating with drug traffickers.
Calderon has relied on the military to fight cartels, and many retired army officers have taken the helm of local police forces.
In April, retired Mexican army Col. Arturo Navarro was fatally shot as he drove home in Piedras Negras, across the border from Eagle Pass, Texas — less than three weeks after he took over the local force with the aim of purging alleged corruption.
Officers complained that his leadership left them fearful of reprisal attacks from gangs.
Mexico's drug violence has claimed more than 10,800 lives since 2006, when Calderon launched his anti-drug campaign. About 45,000 soldiers have been deployed to drug-plagued areas.
On Monday, soldiers detained the nephew of former Gulf cartel kingpin Osiel Cardenas in the border city of Matamoros, across from Brownsville, Texas. Mario Alberto Cardenas admitted heading a cocaine trafficking cell for the cartel along with his uncle, Ezequiel Cardenas, one of Mexico's most wanted drug smugglers, the defense department said in a statement.
Osiel Cardenas was detained in 2003 in Matamoros and extradited to Texas in 2007. He is set to stand trial in September.