el paso, texas...;The brutality of a massacre at Juárez drug rehabilitation center in which 18 people were killed shocked a city already plagued with record-breaking violence.

A motive for the attack was under investigation, but it appeared to be linked to feuding drug trafficking groups.

Chihuahua state public safety secretary Victor Valencia said such drug centers are sometimes fronts for criminal gangs and one narcotics expert said the slayings are unlikely make much of a difference in the overall balance of power in the drug war.

The massacre is believed to be the worst multiple shooting ever in Juárez, which is a battleground in a war between the Juárez and Sinaloa drug cartels that has left more than 3,000 dead since January 2008.

"This type of terrorist acts can't be foreseen because I'm sure if the federal government, the state or city had known of this attack,measures would have been taken to stop the criminals," said Guillermo Dowell Delgado, who is the equivalent of a city manager.
The incident is at least the third and largest mass shooting at drug treatment centers in Juárez since last year.

The city's public safety secretary, retired Mexican army Gen. Julian David Rivera Breton, on Thursday ordered extra police patrols and the installation of panic buttons at other drug treatment facilities.

Shortly before 8 p.m. Wednesday, an unknown number of gunmen with assault rifles burst into the Casa El Aliviane drug rehab center on 1243 Uranio, west of downtown Juárez near the Rio Grande across Downtown El Paso.

The gunmen demanded all 20 people in the building line up in a hallway, said Joint Operation Chihuahua spokesman Enrique Torres.

The assailants then began firing their AK-47 rifles.

Sixteen men died piled on each other at the scene. Four people were taken to a hospital in serious condition where two of them died a short time later.

Officials had initially reported 19 people had died and six others were wounded. Officials said the other two wounded remained in serious condition.

The wounded and dead left behind "a river of blood," a police officer at the scene told the Norte de Ciudad Juárez newspaper Wednesday night at a scene filled with soldiers, police and a military helicopter circling overhead. There have been no arrests.
The center in Juárez is not legally affiliated with Aliviane of El Paso treatment center.

"We feel a deep sorrow for the unfortunate incident that has occurred at the El Aliviane drug rehabilitation center in Ciudad Juárez," Aliviane of El Paso officials said in a statement.

The victims of the shooting were men ranging in age from 17 to 51. Some were identified through tattoos, state police said.

Authorities said a motive for the killing was under investigation and would not confirm rumors the victims were Aztecas gang members.

The Aztecas and their U.S.-based brethren the Barrio Azteca prison gang are known to run drug treatment centers for their members in Juárez, FBI agents have said. The gang is allied with La Linea, as the Juárez drug cartel is also known.

"I think the significance (in the drug rehab attack) is in the number of people killed but these were street-level people, (drug) users or gang members," said Robert Almonte, executive director of the Texas Narcotics Officers Association.

"Why would anybody want to kill drug addicts? Because they are affiliated with a cartel," Almonte said. "It's a sad situation."

In August 2008, eight men were killed during a religious service at one drug rehab center. Last June, gunmen shot and killed five of 50 patients at another center with the survivors escaping by running out a back door and jumping over walls.

Drug treatment centers can be a good front to find recruits to do the bidding of Mexican drug cartels, narcotics experts said.

For example, the La Familia Michoacana drug cartel in western Mexico spreads its religious-influenced message of empowerment and self-renewal among drug addicts, alcoholics and delinquents to build a cult of true believers, said an essay by George W. Grayson, a government professor at the College of William and Mary who has extensively studied La Familia cartel.

The shooting at the drug rehab center puts more emphasis on the violence that continues to grip the city. The month of August was record-shattering and ended with more than 307 homicides.

In one month, Juárez has had nearly as many deaths as some major American cities all of last year.

In 2008, Los Angeles had 384 murders, Detroit had 306 and Philadelphia recorded 331, according to the FBI's preliminary Uniform Crime Report.

In other developments Thursday, Mexican military officials said soldiers arrested Juan Gerardo Hernandez del Real, 24, alias "El Moreno," who is accused of being involved in 13 killings, including last month's fatal shooting of an army captain inside the Bol-Bol bowling alley.

And Wednesday, soldiers arrested Javier Martinez Gomez, 39, aka "El Tijuas," 39, and Armando Rosales Arteaga, 44, aka "El Mandis." Martinez is suspected in 13 deaths and Rosales is suspected in 24 killings.

All three suspects allegedly belong to La Linea with Rosales allegedly working for a cartel cell run by "the brothers Araiza" transporting cocaine and marijuana from Chihuahua City, officials said.

The three arrests come after the recent capture of two hit squads suspected in taking part in more than 200 murders.