Egypt's prosecutor general ordered Monday the investigation of two Muslim Brotherhood leaders on allegations that they instigated violence against protesters critical of the country's new president, who hails from the Islamist movement, a prosecution official said.

The decision to question Mohammed el-Beltagy and Essam el-Erian follows clashes Friday between supporters and critics of President Mohammed Morsi that left more than 100 people injured.

It was based on complaints from female activists who accused the two leading members of inciting Brotherhood protesters to attack them and other protesters during what started out as a peaceful demonstration against policies of the newly elected Morsi.

The protests quickly turned into prolonged clashes between supporters of Morsi, who decided to demonstrate on the same day as critics of Morsi. It was the first such violence since Morsi took office over three months ago, with liberal and secular activists erupting with anger and accusing the Muslim Brotherhood of trying to take over the country.

The investigation comes on the heels of a showdown between Morsi and the prosecutor general, Abdel-Meguid Mahmoud. Morsi tried to remove the prosecutor from office, but backed down after pressure from judges. The judges said Morsi was trampling on the independence of the judiciary. Egyptian law protects the prosecutor general from being fired by the president.

After meeting with the prosecutor general, Morsi's vice president said a "misunderstanding" was to blame for the showdown. He said Mahmoud will remain in his post, a move hailed by judges as a victory for their camp.

In a sign tensions between the president's supporters and the judiciary may be lingering, el-Beltagy, after hearing the investigation may be imminent, wrote on his Facebook page that he was ready to be interrogated but urged the prosecutor to act equally fast on complaints he filed against former regime officials.

El-Beltagy is a leading member of the 100-person panel tasked with writing Egypt's constitution.

El-Erian, currently a candidate for the presidency of the Brotherhood's political party, could not be immediately reached for comment.

The prosecutor general is a holdover from the days of now-ousted President Hosni Mubarak.

The Friday pro-Morsi demonstrators were rallying in support of Morsi's decision to remove Mahmoud, who many have blamed for inadequate investigations, either intentionally or out of incompetence, into probes accusing former regime officials of responsibility in the killing of hundreds of protesters against Mubarak.

The move to remove the prosecutor general and the subsequent protest followed a mass acquittal of more than 20 former regime officials put on trial for their role in orchestrating violence against protesters during the 18-day uprising against Mubarak, in a widely televised attack known as the "Camel Battle" in February 2011.

Morsi's critics accused the Brotherhood of holding a simultaneous rally to "hijack" Tahrir square, and silence critics of the Islamist president.

The violence erupted when Morsi supporters stormed a stage set up by the rival camp, angered by chants they perceived as insults to the president. The Islamist backers smashed loudspeakers and tore the wooden stage down, witnesses said.

The uproar ensued as more supporters of the liberal-secular rally poured into the square. Young men from both sides tore up chunks of concrete and paving stones to hurl while others hit each other with sticks. Gunshots were heard. Youths making V-for-victory signs with their hands set fire to two empty Brotherhood buses.

Brotherhood officials have denied their members were behind the violence, saying in a statement Saturday that "thugs" posing as members of the group were responsible. They also accused the anti-Morsi protesters of initiating the clashes by insulting the Brotherhood and its leader.

Mahmoud, the prosecutor general, asked intelligence and security agencies to handover tapes and videos of the protests from cameras around the square to help in the investigation.

A security official said three others including a minor suspected of burning empty Brotherhood buses at the protest were ordered detained pending investigation. Both officials spoke anonymously as they were not allowed to talk to reporters.

Meanwhile, the illicit gains authorities have ordered the detention of the former parliament speaker, Fathi Sorour, for 15 days pending investigation into corruption charges, Egypt's state news agency reported.

Sorour was among 24 former regime officials that were released after the acquittals in the Camel Battle trial.