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The death toll from the wave of protests and clashes across Egypt has risen to 20, hospital spokesmen told Efe Monday.
At least 12 people died in the past few hours in clashes between opposition members and Islamists at the Muslim Brotherhood's headquarters in Cairo.
Five other people died in clashes in front of the offices of the governing Freedom and Justice Party, the political wing of the Muslim Brotherhood, in the city of Asyut.
A total of 713 people, including at least one police officer, have been wounded in the protests, which started peacefully on Sunday and turned violent after nightfall.
The armed forces, meanwhile, gave political leaders 48 hours to do their jobs and reach an agreement as the protests continued.
A roadmap for the future will be announced and its terms imposed "if the people's demands are not met" within the 48-hour timeframe, the armed forces said in a statement read on state television.
"The armed forces are giving 48 hours as the last opportunity for the political forces to take responsibility at this historic time in the country, which is not going to forgive any force that fails to assume its responsibility," the armed forces said.
The armed forces warned on June 23 that they would "not remain quiet" if Egypt slipped into a "hard to control" conflict.
Protesters demanding that President Mohammed Mursi step down attacked the Cairo headquarters of the Muslim Brotherhood, which the head of state belonged to until he took office, with Molotov cocktails and stones.
Muslim Brotherhood members fired shots at the protesters from inside the building, which the mob eventually took and burned.
The protesters took control of the building early Monday and set fire to all the floor, causing extensive damage.
The Muslim Brotherhood's offices were looted and protesters hauled away electronic equipment, furniture and documents.
The demonstrators set off at least two gas cylinders at the building's entrance and fired shots at the headquarters, wounding several people, a Muslim Brotherhood spokesman told the official Mena news agency.
The attack was carried out amid a "total absence of the security forces," the spokesman said.
Hundreds of people spent the night in tents on Tahrir Square and resumed the protests against Mursi on Monday, while the opposition called on the president to step down by Tuesday.
Sunday's protests were the largest in Egypt since the revolution that ousted Hosni Mubarak's regime in February 2011. EFE