UPDATE, 2:40pm, Saturday:
CAIRO (AP) - Egypt president's office says Mohamed ElBaradei has not been named PM as earlier announced.
CAIRO (AP) -- An opposition spokesman says pro-reform leader Mohamed ElBaradei has been named interim prime minister.
Khaled Dawoud of the National Salvation Front, the main opposition grouping, told The Associated Press that interim President Adly Mansour will swear in ElBaradei on Saturday evening.
ElBaradei has led the opposition to autocrat Hosni Mubarak, toppled by a popular uprising in 2011, and later to the Islamist president Mohammed Morsi, forced out by the military earlier this week in a move that has led to a new round of chaos in Egypt.
ElBaradei is a Nobel peace Laureate and a former director of the U.N. nuclear watchdog.
Meanwhile, protesters and security forces appear to be preparing for more battles in Cairo.
In a suburb that's been a rallying point for the Muslim Brotherhood, lines of fighters armed with homemade weapons and wearing body armor have been gathering at road blocks affixed with pictures of ousted leader Mohammed Morsi. Meanwhile, in a nearby neighborhood, people have been chanting against Morsi and honking car horns in appreciation of roadblocks manned by Egypt's military.
Egyptian security forces are bolstering positions near a protest camp of Morsi supporters,
Dozens were killed in fighting overnight.