CAIRO - Egypt's embattled Muslim Brotherhood on Tuesday named a hardline new "general guide" hours after authorities arrested the movement's senior leader, sources said.
The temporary appointment of Mahmoud Ezzat, a 69-year-old doctor, came amid a deepening crackdown on the Islamist movement of ousted President Mohammed Morsi.
"In the media, Ezzat has been personified as the Brotherhood’s 'iron man,' embodying its reputation for top-down decision-making," U.S.-based think tank the Washington Institute said in an online bio.
Ezzat will be filling in for Mohammed Badie, 70, who was detained at an apartment in northeast Cairo early on Tuesday. His arrest followed the deaths of 25 police officers in a militant ambush in Sinai and a court ruling announcing the possibility that the jailed ex-President Hosni Mubarak could soon walk free from prison.
According to the Washington Institute, Ezzat "is currently a professor in Zagazig University’s College of Medicine, where his colleagues have included [former] President Morsi."
Badie's arrest is a blow to Muslim Brotherhood at a time when authorities are cracking down on its leaders and mid-ranking officials across the country.
Also on Tuesday, the Egyptian military said it had killed a journalist working for state-run newspaper Al Ahram and wounded another at a military checkpoint near the city of Alexandria during the dusk-to-dawn curfew.
The two journalists were driving towards a checkpoint but failed to heed warnings to slow down or stop, the military said in a statement. After warning shots were ignored, driver Tareq Abdul Raouf, a reporter with Al Ahram newspaper. That forced the vehicle to swerve and ram into a light pole, which injured a second passenger, journalist Hamed Fathy El Berbery, who is with another state-run newspaper Al Gomhouria.
"No excessive gunfire was opened on the car in question nor any killing of those in it intended," the statement said, calling on people to adhere to the curfew to facilitate the work of security services.
Journalists are exempt from the curfew, which the government ordered after security forces broke up two pro-Morsi protest camps last week. Around 900 people, including more than 100 soldiers and police, have been killed since then.
The court ruling potentially paving the way for former authoritarian president Mubarak's release poses a dilemma for the military-backed government.
Mubarak has been in detention since April 2011 and is widely despised for widespread abuses and repression during his 29 years in power.
He was found guilty and sentenced to life in prison last year for failing to stop the killing of some 900 protesters in the 18-day uprising which ended his rule. His sentence was overturned on appeal and he is now being retried, along with his security chief and six top police commanders.
NBC News' F. Brinley Bruton and Reuters contributed to this report.