At least eight people were killed early Monday when gunmen opened fire in a bar in drug-plagued Ciudad Juarez on the Mexico-Texas border.
Chihuahua state official Arturo Sandoval said three others were hospitalized after the attack that killed seven men and one woman.
Ciudad Juarez is one of Mexico's deadliest cities, with more than 1,300 killings so far this year. The federal government has sent thousands of soldiers to crack down on drug cartels, which have responded with unprecedented violence.
Many of the killings are the result of battles between rival drug smugglers for lucrative routes into the United States.
In the northern city of Monterrey, four gunmen died in a shootout Monday with soldiers and three other suspects were detained, said Nuevo Leon state Public Safety Director Aldo Fasci. Three soldiers suffered light injuries in the clash.
Fasci said the confrontation, which included a car chase, led soldiers to a home where an additional five men and a woman apparently connected to the case were detained.
Drug gangs in northern Mexico frequently operate out of "safe houses" in otherwise normal neighborhoods.
In the western city of Guadalajara, the manager of a singer who specialized in drug ballads died Monday of wounds he suffered in a weekend attack that killed the musician.
Jorge Altamirano Pelayo served as manager for Carlos Vicente Ocaranza, who was shot to death outside a bar Saturday. Ocaranza was known for singing "narco-corrido" ballads that often glorify the feats of drug traffickers.
Ocaranza was better known as "El Loco Elizalde," or The Crazy Elizalde, a reference to his distant relation by marriage to Valentin Elizalde, a much more famous musician who was also killed by gunshots in 2006.
Prosecutors in western Jalisco state, where Guadalajara is located, said the assailants fled on a motorcycle. Local police say Ocaranza received death threats in the past and are investigating possible drug gang links to the crime.
Drug violence has claimed more than 11,000 lives in Mexico since President Felipe Calderon took office in late 2006 and launched a major offensive against cartels.
The U.S. State Department said Monday that the Obama administration last week sent Congress a favorable report on Mexico's human rights record that could allow the release of $100 million in U.S. aid to help the country fight narcotics traffickers.
In early August, Democratic Sen. Patrick Leahy of Vermont stopped the release of the report on the Merida Initiative, a $1.4 billion, three-year aid package, saying it was premature to give Mexico a passing grade on human rights.
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