CIUDAD JUAREZ, Mexico — At least 30 gunmen burst into a drug rehabilitation center in a Mexican border-state capital and opened fire, killing 19 men and wounding four people, police said. Gunmen also killed 20 people in another drug-plagued northern city.
The killings marked one of the bloodiest weeks ever in Mexico and came just weeks after authorities discovered 55 bodies in an abandoned silver mine, presumably victims of the country's drug violence.
The bullet-riddled bodies of 18 men and two women were found Friday in five parts of Ciudad Madero, a city in the northeastern state of Tamaulipas, where violence has surged this year amid a turf battle between the Gulf cartel and its former ally, the Zetas gang of hit men.
Police had no information on suspects.
It was the deadliest day of drug violence in Tamaulipas since 18 gunmen died in clashes with soldiers in April.
Another round of killings occurred late Thursday at the Faith and Life center in Chihuahua city, about 210 miles south of Ciudad Juarez and the border with El Paso, Texas, state police spokesman Fidel Banuelos said.
A day earlier unidentified assailants killed one man and wounded another at a rehab center in Ciudad Juarez, which has become one of the world's most deadly cities because of drug violence.
More than 60 people have died in mass shootings at rehab clinics in a little less than two years. Police have said two of Mexico's six major drug cartels are exploiting the centers to recruit hit men and drug smugglers, often threatening to kill those who don't cooperate. Others are killed for failing to pay for drugs or betraying a dealer.
The men at the Faith and Life center were roused out of bed shortly before 11 p.m. and placed face-down along a hallway, the center's director, Cristian Rey Ramirez, told the Associated Press.
Ramirez was alerted to the attack by a telephone call from the center's pastor.
"He tells me, 'You know what, come here because they just killed everyone,' " Rey said. "There was no warning."
The attackers left messages accusing the victims of being criminals, Banuelos said.
Four other people were hospitalized, two in critical condition and two in serious condition, officials said.
Most of the victims ranged in age from 30 to 40, with some older, and included a blind man, said the Rev. Rene Castillo, a minister who gives weekly sermons at the center, which opened 11 years ago. It was the first such attack on the center, although two men and a woman were kidnapped there in April 2008 while attending a memorial service, Banuelos said.
The three-story, baby-blue concrete building houses addicts for 90 days, although some of those attacked had been there for up to two years, Castillo said.
President Felipe Calderon, whose war with drug cartels has seen nearly 23,000 people killed since he took office in late 2006, issued a statement condemning the shootings.
"They are outrageous acts that reinforce the conviction of the need to fight criminal groups who carry out such barbaric acts with full legal force," he said.