Rising drug violence in Mexico's border region has prompted Southern Arizona's largest military installation to issue new restrictions on troop travel and a warning to military families and civilian staff members to stay away.
As of Tuesday, nearly 7,000 troops at Fort Huachuca in Sierra Vista must get prior approval from the Army post's top brass in order to cross the border. Violators would be subject to military discipline.
Another 11,000 or so family members, civilian staff members and contractors at the fort are "strongly urged" not to visit Mexican cities such as Naco, Agua Prieta and Nogales, a popular shopping, dining and nightlife destination.
The Army can't legally stop family members and civilian workers from visiting Mexico, but it is warning them not to do so for their own safety, said Tanja Linton, a spokeswoman for Fort Huachuca.
The post is about 75 miles southeast of Tucson and less than 20 miles from Mexico.
"We are constantly monitoring this situation in the interest of protecting our people," Linton said.
Fort Huachuca's travel restrictions are less severe than those at Fort Hood in Texas, the nation's largest Army post, where soldiers are banned outright from traveling to numerous Mexican border cities, including Nogales.
Travel restrictions are set by installation commanders and vary with local conditions, Linton said. Fort Huachuca's new restrictions could be tightened further, or eased, if warranted, she said.
In May 2007, for example, Fort Huachuca banned local soldiers from Mexico for a week after violence erupted in the town of Cananea. More recently, the fort has allowed cross-border travel with approval from lower-level commanders.
Drug-cartel-fueled violence has reached unprecedented levels this year in the Mexican border state of Sonora and specifically in Nogales, where official government figures show homicides have tripled in recent years. Nearly 100 killings have occurred so far this year, up from 52 in 2007 and 35 in 2006.
The violence is attributed to an ongoing battle between drug cartels for the corridor - the most desired piece of real estate along the U.S.-Mexico border.