MEXICO CITY , Mexico ( CNN ) -- A mayor in Mexican President Felipe Calderon 's home state was ambushed and killed by a group of heavily armed men as he returned to his house , news reports said . It was the second assassination attempt in eight days on Vista Hermosa Mayor Octavio Manuel Carrillo Castellanos , the Cambio de Michoacan newspaper said on its Web site Wednesday . Carillo was pulling up to his home around 6 p.m. Tuesday when at least two men got out of a vehicle and opened fire . There were conflicting reports over whether a second vehicle with armed men may have been involved . Family and others came to Carillo 's aid while a police officer stationed at his house called for help , Cambio de Michoacan said . Carillo was taken to a nearby hospital , where he died around 7:20 p.m.. Officials said they did not have a motive or know if the mayor had received any threats . But El Excelsior newspaper reported that investigators are looking into Carillo 's recent firing of a Vista Hermosa police commander and an officer . Carillo , who took office on January 1 , 2008 , was the second mayor in the Pacific coast state of Michoacan killed in the last eight months . Marcelo Ibarra Villa , the mayor of Villa Madero , was ambushed in June while riding in his truck with his wife , El Excelsior said . The gunmen escaped in both instances . Tuesday 's killing came on Mexican Flag Day , just hours after Calderon vowed that his government would continue to battle the drug cartels that have ravaged the country . The mayor 's death also came four days after the sudden resignation of the police chief in Ciudad Juarez , across the border from El Paso , Texas . Police Chief Roberto Orduna had received death threats from local drug cartels and resigned after the recent deaths of eight police officers under his command . Violent deaths reached record levels in Mexico last year as drug cartels battle each other and the Mexican government . More than 5,400 killings were reported in 2008 , more than double the tally in 2007 . Authorities and analysts said a new record could be set this year . Narcotraffickers have adopted a campaign of intimidation against authorities , and the deaths of police , mayors and other officials have become common . Last year , more than 100 police were killed in Ciudad Juarez in attacks blamed on organized crime . `` They started killing police officers when they were going home or getting into police cars , '' Mayor Jose Reyes Ferriz told reporters last week . Just last week , the city 's police director of operations was gunned down in his car . Another police officer and a prison guard were found dead Friday morning . On Friday , the U.S. State Department renewed a travel alert for Americans considering a visit to Mexico . `` The situation in Ciudad Juarez is of special concern , '' the alert said . `` Mexican authorities report that more than 1,800 people have been killed in the city since January 2008 . Additionally , this city of 1.6 million people experienced more than 17,000 car thefts and 1,650 carjackings in 2008 . '' In addition , the University of Arizona warned its students against going to Mexico on spring break this year , and Arizona State University is considering the same advisory . `` These are flat-out organized crime groups like we think of any other organized crime groups . They are not a small gang on the corner . These are large organizations , '' said David Denlinger , chief of the Arizona Department of Public Safety .
U.S. State Department Mayor Octavio Manuel Carrillo Castellanos killed outside home . Manuel Carrillo Castellanos is second mayor in Pacific coast state of Michoacan killed in last year . Drug traffickers have adopted campaign of intimidation against authorities . U.S. State Department issues travel alert for Americans considering visit to El Paso .