From the State Department:

The Department of State urges U.S. citizens who travel to Algeria to evaluate carefully the risks posed to their personal safety. Terrorist attacks, including bombings, false roadblocks, kidnappings, and ambushes occur regularly, particularly in rural areas such as the Kabylie region of the country. The use of suicide bomb attacks, particularly vehicle-borne attacks, emerged as a terrorist tactic in Algeria, including in the capital, beginning in 2007. The group that claimed credit for the December 11, 2007 suicide car-bomb attacks in Algiers has pledged more attacks against foreign targets and specifically against U.S. targets. The same group is believed to operate in southern Algeria and to be linked to the kidnapping in February 2011 of a western tourist in the southeast, near the Nigerian border. This regional kidnapping threat was noted in the Department of State’s Worldwide Caution dated January 24, 2012.

The Department of State recommends that U.S. citizens avoid overland travel in Algeria. U.S. citizens who reside in or travel to Algeria should take personal security measures to include stocking adequate reserves of medicine, food, and water for use during an emergency. Additionally, sporadic episodes of civil unrest have been known to occur, such as the riots in Algiers and many other cities from January 2011 to the present. U.S. citizens should avoid large crowds and maintain security awareness at all times. Visitors to Algeria are advised to stay only in hotels where adequate security is provided. All visitors to Algeria should remain alert, avoid predictable travel patterns and maintain a low profile. ...

The next Algerian parliamentary elections will be held on May 10, 2012. U.S. citizens should avoid demonstrations and political rallies of all kinds. Most political gatherings are peaceful, but they can turn violent without notice. ...

U.S. State Department Warning