Egypt’s Constitutional Court top Judge, Adli Mansour, is to be sworn in as interim leader, following the ouster of President Mohammed Morsi by the Egyptian Army.
According to the BBC Middle-East service, this announcement was made Wednesday, by the Army Chief Gen Abdul Fattah al-Sisi.
It has also been reported that Mohammed Morsi has been placed under house arrest.
Gen Sisi said Mr Morsi had “failed to meet the demands of the people”.
The removal of the president followed four days of mass protests against Mr Morsi and an ultimatum issued by the military, which expired on Wednesday afternoon.
Protesters accused him and his party, the Muslim Brotherhood backed, Freedom and Justice Party of pursuing an Islamist agenda for the country and of failing to tackle Egypt’s economic problems
The BBC’s Kevin Connolly in Cairo says the president had appeared to protesters to be economically out of his depth, and had not given them the reassurances they wanted that he could address rampant poverty.
About 50 people have died since the latest unrest began on Sunday.
Celebrations were held throughout the night in Cairo’s Tahrir Square by Mohammed Morsi’s opponents, as the army announced it had suspended the constitution and pledged to hold new elections.
But a number of people were killed as clashes erupted overnight between Morsi supporters and the security forces in Cairo and Alexandria.
Gehad el-Haddad, a spokesman for Mr Morsi’s Muslim Brotherhood, told the BBC the ousted leader had been put under house arrest and the “entire presidential team” was in detention.
Mr Haddad’s father, senior Morsi aide Essam el-Haddad, and Saad al-Katatni, head of the Brotherhood’s political wing, are among those held.
US President Barack Obama has said he is “deeply concerned” by the latest turn of events and called for a swift return to civilian rule.
Find below Key Moments In Egypt’s Political Crisis
• 11 February 2011 – Hosni Mubarak resigns as president after two weeks of massive street protests and violent clashes
• January 2012 – Muslim Brotherhood-affiliated Freedom and Justice Party wins parliamentary elections with almost half of votes
• June 2012 – Mohammed Morsi becomes Egypt’s first freely elected president
• 22 November 2012 – Mr Morsi issues a controversial decree granting himself extensive powers – after angry protests he eventually rescinds most of it
• 3 July 2013 – The army suspends the constitution and removes Mr Morsi from power