Ciudad Juarez (Mexico), Apr 22 (IANS/EFE): At least 13 people were gunned down and four wounded in an attack by suspected cartel gunmen at a bar in the northern Mexican city of Chihuahua, authorities said.

"Thus far the preliminary report is 13 dead and four wounded," Carlos Gonzalez, spokesman for the Chihuahua state Attorney General's Office, told EFE.

The attack occurred Friday night when several armed assailants entered the El Colorado bar on the city's north side and opened fire with automatic rifles, Gonzalez said.

Chihuahua has been among the states hardest hit by violence pitting drug cartels fighting over smuggling routes to the United States.

On Feb 4, a shootout at a bar in that same city left nine people dead, including a police officer and five musicians, and 11 wounded.

Over the past four years, the border state has accounted for nearly 30 percent of the more than 50,000 drug-related homicides nationwide.

Many of the killings there have occurred in Ciudad Juarez, a sprawling metropolis across from El Paso, Texas, that is considered among the world's deadliest cities.