US warns on travel where agents shot in Mexico

The U.S. government has barred its employees from traveling to the Mexican state where two U.S. federal agents were shot this week.

An alert issued Thursday by the U.S. Consulate in Monterrey says American citizens also are urged not to travel to San Luis Potosi state.

The two Immigration and Customs Enforcement agents were attacked Tuesday on a highway in the state. One was killed and the other wounded.

The consulate also says U.S. citizens should "maintain a heightened sense of alert" while traveling in four central Mexico states surrounding San Luis Potosi.

The warning includes the popular tourist cities of Guanajuato and San Miguel de Allende. The latter is a picturesque town that is home to many U.S. expatriates and retirees.