At least 30 gunmen stormed a drug rehabilitation center in a Mexican border state capital and opened fire, killing 19 men and wounding several others, police said. The killings happened late Thursday at the Faith and Life center in Chihuahua city, about 350 kilometers south of Ciudad Juarez and the border with El Paso Texas. The victims were awakened shortly before 11 p.m. and placed face-down along a hallway, the center's director, Cristian Rey Ramirez, told the Associated Press. He said he was alerted to the attack by a center employee who telephoned him. “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, Chihuahua state police spokesman Fidel Banuelos said. President Felipe Calderon, whose war against drug cartels has claimed almost 23,000 lives since late 2006, issued a statement Friday 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. Police have said two of Mexico's six major drug cartels are exploiting rehabilitation centers to recruit assassins and drug smugglers, often threatening to kill those who do not cooperate. Others are killed for failing to pay for drugs or betraying a drug dealer. More than 60 people have died in mass shootings at rehabilitation clinics in less than two years.