The U.S. State Department barred travel by officials to the 15th century ruins of Machu Picchu, Peru’s top tourist destination, citing a heightened risk of kidnapping.

A criminal organization may be planning to abduct U.S. tourists visiting the mountain Inca sanctuary and the surrounding Cuzco region, the U.S. embassy in Lima said in a statement posted on its website yesterday.

“Personal travel by U.S. Embassy personnel to the Cuzco region, including Machu Picchu, has been prohibited and official travel is severely restricted as a result of this threat,” the embassy said. “Possible targets and methods are not known and the threat is credible at least through the end of February 2013.”

About 1.1 million tourists visited the citadel and Incan ruins in the surrounding areas last year, including 762,000 foreigners, according to the Tourism Observatory of Peru. Located 1,165 kilometers (725 miles) southeast of Lima, Machu Picchu is the mainstay of the country’s tourist industry, which generated $3.3 billion in revenue last year.

The embassy said it is confident of the Peruvian government’s efforts to protect tourists.

Editors: Bill Faries and Philip Sanders.

To contact the reporter on this story: John Quigley in Lima at [email protected] contact the editor responsible for this story: Andre Soliani at [email protected]

Photo Credit: Early morning in Machu Picchu before the hoards of tourists arrive. Sandi / Flickr