WASHINGTON - The US State Department on Thursday issued a travel warning on Algeria, citing continuing threat posed by terrorism in the North African nation.

In an updated travel advisory, the department urged US citizens traveling to Algeria to "evaluate carefully the risks posed to their personal safety," saying "There is a high threat of terrorism and kidnappings in Algeria."

The department also named al-Qaida in the Islamic Maghreb and the Movement for Unity and Jihad in West Africa as two groups that are active and engaged in bombings and kidnappings in Algeria.

"Although the major cities are heavily policed, attacks could still potentially take place," the department warned. "The majority of terrorist attacks, including bombings, false roadblocks, kidnappings and ambushes occur in areas of the country east and south of Algiers."

The warning came as anti-American protests broke out in Libya, Egypt, Tunisia, Yemen, Iran and Iraq starting from Tuesday over an alleged US-made movie that protesters say insults Prophet Mohammed.

US Ambassador to Libya Chris Stevens and three other Americans were killed Tuesday night when hundreds of protesters broke into and set ablaze the US consulate building in Libya's eastern city of Benghazi.