CAIRO — Egypt descended into political turmoil on Wednesday over the constitution drafted by Islamist allies of President Mohammed Morsi, and at least 211 people were wounded as supporters and opponents battled each other with firebombs, rocks, and sticks outside the presidential palace.
Four more presidential aides resigned in protest over Morsi's handling of the crisis, and a key opponent of the Islamist president likened Morsi's rule to that of the ousted authoritarian leader Hosni Mubarak.
Both sides were digging in for a long struggle, with the opposition vowing more protests and rejecting any dialogue unless the charter is rescinded, and Morsi pressing relentlessly forward with plans for a Dec. 15 constitutional referendum.
''The solution is to go to the ballot box,'' said Mahmoud Ghozlan, a spokesman for Morsi's Muslim Brotherhood, calling the charter ''the best constitution Egypt ever had.''
The clashes outside the presidential palace marked an escalation in the deepening crisis. It was the first time supporters of rival camps fought each other since last year's anti-Mubarak uprising, when loyalists sent sword-wielding supporters on horses and camels into Tahrir square in what became one of the uprising's bloodiest days.
The large scale and intensity of the fighting marked a milestone in Egypt's rapidly entrenched schism, pitting Morsi's Brotherhood and ultra-conservative Islamists in one camp against liberals, leftists, and Christians in the other.
The violence spread to other parts of the country later Wednesday. Anti-Morsi protesters stormed and set ablaze the Brotherhood offices in Suez and Ismailia, and there were clashes in the industrial city of Mahallah and the province of Menoufiyah in the Nile Delta.
Compounding Morsi's woes, four of his advisers resigned, joining two other members of his 17-member advisory panel who have abandoned him.
Mohamed ElBaradei, a leading opposition advocate, said Morsi's rule was ''no different'' than Mubarak's. ''In fact, it is perhaps even worse,'' the Nobel Peace Prize laureate told a news conference after he accused the president's supporters of a ''vicious and deliberate'' attack on peaceful demonstrators.
''Cancel the constitutional declarations, postpone the referendum, stop the bloodshed, and enter a direct dialogue with the national forces,'' he wrote on Twitter, addressing Morsi. ''History will give no mercy and the people will not forget.''
The opposition is demanding that Morsi rescind the decrees giving him nearly unrestricted powers and shelve the controversial draft constitution the president's Islamist allies rushed through last week in an all-night session.
The huge scale of the opposition protests has dealt a blow to the legitimacy of the new charter, which Morsi's opponents contend allows religious authorities too much influence over legislation, threatens to restrict freedom of expression, and opens the door to Islamist control over day-to-day life.
In addition, the country's powerful judges say they will not take on their customary role of overseeing the referendum. Zaghloul el-Balshi, secretary general of the state committee organizing the referendum, said on the private Al-Hayat television that he would not go ahead with preparations until the fighting stops and Morsi rescinds his decrees.
The new attorney general, a Morsi appointee, hit back, ordering an investigation of Ahmed El-Zind, chairman of the judges' union.
Wednesday's clashes began when thousands of Morsi's supporters descended on an area near the presidential palace where some 300 of his opponents were staging a sit-in. The Islamists chased the protesters away and tore down their tents.
After a brief lull, hundreds of Morsi opponents arrived and began throwing firebombs at the president's backers, who responded with rocks. The clashes continued well after nightfall. The deployment of hundreds of riot police did not stop the fighting.
''I voted for Morsi to get rid of Hosni Mubarak. I now regret it,'' Nadia el-Shafie yelled at Brotherhood supporters.
"God made this revolution, not you!'' the tearful woman said as she was led away.