A spate of killings by drug gangs claimed at least 46 lives last weekend in Mexico, including at least 16 young people shot dead at a high school party.
The first attack took place on Sunday in Ciudad Juarez, when gunmen drove up to a house in several cars, first shooting at people gathered outside, then chasing and cornering some of the partygoers.
Most of the 16 or more victims were youths, according to José Reyes, mayor of the city of 1.3 million inhabitants just across the border from El Paso, Texas.
Military spokesman Enrique Torres said the gunmen had apparently been looking for someone who was not even at the party, before shooting indiscriminately at the crowd.
Shortly after in Torreon, in the northern state of Coahuila, 10 people were killed when gunmen opened fire on a crowd inside a bar.
Federal police confronted suspected members of Mexico's 'Los Zetas' drug cartel in two successive shootouts late yesterday that left seven traffickers and one policeman dead in Torreon.
Earlier, gunmen opened fire at a bar in Ciudad Juarez, killing five people and injuring six others, police said.
Meanwhile a clash between two organised crime groups in Magdalena, Sonora state, left seven people dead.
The Juarez cartel led by Vicente Carrillo and the Sinaloa cartel led by Joaquin 'El Chapo' Guzman are battling for control in Chihuahua state, authorities say.
The war waged by rival drug cartels in Mexico has already left more than 15,000 people dead since December 2006 despite a nationwide clampdown on the scourge of violence with the deployment of 50,000 troops and thousands of police.
January was the most violent month of Felipe Calderon's presidency, according to the Milenio daily, which put the death toll at 904, with 17,789 drug-related crimes.
