Embassy officials said Egyptian media reports stated that political movements opposed to the Muslim Brotherhood may direct demonstrations toward U.S. interests.
"This anti-Muslim Brotherhood group of liberal parties is expected to demand that the U.S. reject any support of the Brotherhood," the statement read.
The Muslim Brotherhood took 20 percent of the parliamentary seats by running as independents in 2005, one of the last elections under President Hosni Mubarak. Mohamed Morsi, the first democratically elected president in Egyptian history, hails from the Muslim Brotherhood's Freedom and Justice Party.
Washington has expressed its support for the Morsi administration. In January, he helped broker a truce between Palestinian movement Hamas and Israeli.
Egyptian news agency al-Ahram reports demonstrators chanted slogans against the Muslim Brotherhood and Morsi during demonstrations Friday in Alexandria, Cairo and other metropolitan areas.
Demonstrations in Egypt turned deadly in late January as Egyptians marked the second anniversary of the revolution that dethroned Mubarak.
"As a matter of general practice, U.S. citizens should avoid areas where large gatherings may occur," the embassy statement read.