CIUDAD JUAREZ, Mexico: Gunmen broke into a drug rehabilitation center, lined people against a wall and shot 17 dead in a particularly bloody day in Mexico's relentless drug war. The brazen attack followed the killing of the No 2 security official in President Felipe Calderon's home state.

The attackers on Wednesday broke down the door of El Aliviane center in Ciudad Juarez, lined up their victims against a wall and opened fire, said Arturo Sandoval, a spokesman for the regional prosecutors' office. At least five people were injured.

Authorities had no immediate suspects or information on the victims. Ciudad Juarez, across the border from El Paso, Texas, is Mexico's most violent city, with at least 1,400 people killed this year alone.