Egyptian Islamists brandishing swords have clashed with opponents of a draft constitution in the city of Alexandria as tensions rose on the eve of a referendum on the disputed charter that has plunged the country into weeks of turmoil.
At least 19 people were reported to have been injured in the violence in Alexandria, which broke out after an ultra-conservative cleric urged worshippers to vote "yes" and described the opposition as "followers of infidels".
The crisis pits Egypt's newly empowered Islamists against the country's mainly secular liberals, minorities such as Christians and a large sector of moderate Muslims. Both sides have stepped up their campaigns after weeks of violence.
Thousands of Islamists also filled a square near the presidential palace, raising pictures of President Mohammed Morsi, who has insisted the referendum will begin on Saturday as scheduled despite accusations the entire process has been rushed. A few miles away, the opposition chanted for a "no" vote in a sit-in, exposing the deep rifts in the fight for the identity of post-revolutionary Egypt.
Religious authorities had issued orders that mosques should not be used to manipulate the vote, but several clerics, especially in conservative southern areas, took to the pulpit to tell their congregations that voting in favour of the constitution is seeking victory for Islam.
The crisis began when Mr Morsi, who hails from the Muslim Brotherhood, issued a decree on November 22 giving himself and the assembly writing the draft immunity from judicial oversight so the document could be finalised before an expected court ruling dissolving the panel. Hundreds of thousands took to the streets
The densely written document was then passed by an 85-member assembly mostly composed of Islamists in a marathon session despite a walkout by secular activists and Christians. Mr Morsi rushed it to a vote scheduled for the next two Saturdays, compounding the crisis.
Most of Egypt's judges are refusing to monitor the vote, although authorities said they would be able to meet the legal obligation to have a judge at each polling station. More than 51 million people are registered to vote, with more than 6,000 polling stations in 10 provinces, including Cairo and Alexandria in the first round on Saturday.
The Carter Centre, the international group founded by former US president Jimmy Carter that has been monitoring Egyptian voting since last year's uprising, also said it would not deploy monitors for the referendum because of the government's late release of monitoring regulations.
The opposition reiterated its call for Mr Morsi to postpone the referendum and form a new assembly to draft a new constitution. Ahmed Said, leader of liberal Free Egyptians Party and part of the coalition opposition, said: "History will remember that this regime forced a referendum on the people of Egypt in these harsh circumstances."