1,000 killed in border city of Ciudad Juarez so far this year.

Tue Oct 14, 7:38 PM ET
MEXICO CITY (AFP) - Eleven died in various attacks in Mexico's northern state of Chihuahua, an official said Tuesday, as the United States warned its citizens to increase vigilance when travelling south of the border.
Border areas where rival drug cartels are battling over key routes into the United States are among the worst hit in escalating violence across Mexico this year in which almost 3,500 have died, including civilians.
"Increased levels of violence make it imperative that travellers understand the risks of travel to Mexico," said a new six-monthly State Department travel alert.
Eleven died in attacks in Chihuahua State in the past 24 hours, including a former police commander, said Alejandro Pariente, spokesman for the state attorney general's office, on Tuesday.
Chihuahua is a flashpoint in an increasingly bloody turf war between drug cartels, with more than 1,000 killed in the state's border city of Ciudad Juarez alone so far this year.
"The situation in Ciudad Juarez is of special concern," the State Department said of the city across the border from the US city of El Paso.
"A recent series of muggings near the US Consulate General in Ciudad Juarez has targeted applicants for US visas," it added, as an increasing number of civilians flee the city's violence.
It underlined the use of automatic weapons and grenades by drug cartels, as well as public shootings which have taken place during daylight hours in border cities including Ciudad Juarez, Tijuana and Nogales.
Criminals have followed and harassed US citizens travelling in border areas, sometimes wearing full or partial police or military uniforms, it said.
Dozens of US citizens have been kidnapped across Mexico in recent years, it added, also calling for vigilance during public rallies after an Independence Day grenade attack last month in central Mexico in which eight died.
A government crackdown on drug-related violence, initiated by President Felipe Calderon almost two years ago and including the deployment of 36,000 troops, has showed no sign of stopping the killings.