| CIUDAD JUAREZ, Mexico
CIUDAD JUAREZ, Mexico Suspected drug gang members killed the mayor of a ranching town in northern Mexico on Tuesday in a revenge attack for a mass arrest of hitmen that already sparked the murder of an American Mormon.
Gunmen shot dead Hector Meixueiro in his SUV as he drove to work in Namiquipa, Chihuahua state, in the latest brazen killing to challenge President Felipe Calderon's army-led clampdown on drug cartel violence.
The killing came the same day that drug gangs hung banners in the nearby border city of Ciudad Juarez blaming Meixueiro and the state attorney general for the arrest of 25 cartel hitmen last month.
Breakaway Mormon leader and anti-crime activist Benjamin LeBaron was murdered last week in Chihuahua for his alleged part in capturing the criminals, generating a wave of outrage among his Mexican-American community.
Last year, drug gangs killed the town treasurer in Namiquipa and kidnapped its police chief, who is still missing. Local media said the pair were targeted as revenge for other drug gang arrests in the area.
"Attorney General ... this time it is serious. We know you and the mayor of Namiquipa rounded up the 25 paramilitaries," read the banners hung across Ciudad Juarez on Tuesday.
Soldiers captured the 25 hitmen in a remote part of Chihuahua in early June as traffickers burned down several houses in the area, causing panic among local residents.
Chihuahua has become the bloodiest state in Calderon's drug war as rival traffickers fight over smuggling routes into Texas and road and rail links deep into the United States.
Calderon sent 10,000 troops to Ciudad Juarez in March to try to end the war between the local Juarez cartel and Mexico's most-wanted man, Joaquin "Shorty" Guzman, who leads a powerful group of traffickers from the Pacific state of Sinaloa.
But violence continues unabated across Chihuahua.
The attack on Meixueiro, a rare murder of a politician in the drug war, followed the killings of 12 federal police whose torture-marked bodies were found on Monday, dumped on the side of an isolated highway in the western state of Michoacan.
More than 12,300 people have died in Mexico in a three-way war between rival cartels and the army since Calderon deployed thousands of troops against the cartels in December 2006.
The escalating violence has become a major concern for investors and Washington.
(Additional reporting and Writing by Robin Emmott in Monterrey; editing by Catherine Bremer and Todd Eastham)