Gunmen killed the No. 2 security official in President Felipe Calderon's home state, where drug cartels have launched their biggest offensive yet against Mexico's government.
Attackers in two vehicles intercepted a car being driven by Michoacan deputy public safety director Jose Manuel Revuelta and opened fire, police at the scene said. State officials said Revuelta, two bodyguards and a bystander were killed.
Revuelta had held the post less than a month in the western state, the cradle of the ruthless La Familia drug cartel, which has been blamed for a string of assassinations against federal police and soldiers in recent weeks.
State officials and police officers agreed to discuss the shooting in the state capital of Morelia only on condition of anonymity because they were not authorized to give out the information.
Three blocks from headquarters
An AP reporter at the scene saw the bodies of Revuelta and his bodyguards in the car, which had at least 15 bullet holes in the front windshield. Soldiers and federal police rushed to the site — just three blocks from the headquarters of the Michoacan Public Safety Department — and a helicopter circled overhead.
Calderon first launched his crackdown against drug cartels in Michoacan, sending thousands of federal police and soldiers to his home state after taking office in late 2006. Tens of thousands more have since been deployed to drug hotspots across Mexico.
The government intensified its fight against La Familia since accusing the cartel in a series of deadly attacks across Michoacan in July. In the worst attack, 12 federal agents were slain and their tortured bodies piled along a roadside as a warning for all to see. It was the boldest cartel attack yet on Mexico's government.
Authorities say La Familia was retaliating for the arrest of one of its top members. The cartel controls illicit trades in Michoacan ranging from drug trafficking and methamphetamine production to kidnapping and extortion.
13,500 lives lost
Last week, soldiers captured another suspected La Familia leader, Luis Ricardo Magana, who is alleged to have controlled methamphetamine shipments to the United States for the gang.
Days before his capture, prosecutors detained the mother of reputed La Familia leader Servando "La Tuta" Gomez despite his threat to retaliate if police bothered his family. The woman was released after two days "for lack of evidence" of involvement in the cartel.
Drug gang violence has surged under Calderon, claiming more than 13,500 lives, including more than 1,000 police.
Calderon, whose National Action Party lost big in July legislative elections because of public unease with the violence and an economic recession, defended his battle against drug trafficking in a speech to Congress on Wednesday. He said the government has taken on the cartels as no previous Mexican administration has dared to do.
"As never before, we have weakened the logistical and financial structure of crime," the president told legislators.
In a report submitted to Congress, Calderon said his government has seized 90 tons of cocaine, 5,000 tons of marijuana and some 50,000 illegal weapons. It also said authorities have detained more than 80,000 people linked to organized crime, although it did not specify how many were part of the drug trade.
Mexico also has a major problem with kidnapping gangs and other criminals.