The alert comes in advance of Egypt's first round of presidential elections May 23 and 24, with a possible second round in mid June. Egypt's next president is scheduled to take office by June 30, at the latest.
The warning says "political rallies and demonstrations are likely to occur in the period leading up to and following the elections and during the drafting of a new constitution."
Over the last year, demonstrations in Cairo's Tahrir Square and around the country have seen violent clashes between police and protesters, resulting in some deaths, injuries, and extensive property damage. Several Americans have been arrested during the protests.
The U.S. Department of State "strongly urges U.S. citizens to avoid all demonstrations in Egypt, as even peaceful ones can quickly become violent and a foreigner could become a target of harassment or worse."
It also warns "should security forces block off the area around the U.S. Embassy during demonstrations, Americans "should not attempt to come to the Embassy."
U.S. citizens are advised to remain alert to the local security developments, carry identification and a working cell phone.
The security situation in most tourist centers, including Luxor, Aswan, and the Red Sea Resorts such as Sharm el Sheikh, continues to be calm.
This travel alert takes the place of previous warnings from November 7, 2011 and is due to expire on June 30.