(CNN) -- Gunmen shot dead the No. 2 security official and three others Wednesday in the home state of Mexican President Felipe Calderon, a government spokesman said.
Jose Manuel Revuelta Lopez, the deputy public safety secretary of Mexico's Michoacan state, was killed in a shootout that also claimed the lives of two of his bodyguards and a bystander caught in the crossfire, said Jesus Humberto Adame Ortiz, spokesman for the state.
Revuelta was leaving his office at 5:15 p.m. (6:15 ET) in the state capital, Morelia, when the shooting occurred, Adame said. Suspects had not been identified, he said. Nor was a motive immediately clear.
An unprecedented wave of violence has washed over Mexico since Calderon declared war on drug cartels shortly after coming into office in December 2006. More than 10,000 people have since died, about 1,000 of them police.
The offensive against the government has been especially fierce in Michoacan.
In July, the La Familia Michoacana drug cartel was accused of assaults in a half-dozen cities across the state and of torturing and killing 12 off-duty federal agents and dumping their bodies on a remote road. That violence was thought to have been retaliation for the arrest of a La Familia leader.