Cairo: The opposition accused President Mohamed Morsi's Muslim Brotherhood of attempted "vote rigging" in Saturday's referendum on a new constitution for Egypt.
The National Salvation Front, in a statement, expressed "deep concern... over the number of irregularities and violations in the holding of the referendum," charging it "points to a clear desire for vote rigging by the Muslim Brotherhood."
Earlier, Egyptians started Saturday casting their ballots in 10 of the country’s governorates, including Cairo, in the first round of a referendum on a draft constitution that has sparked deadly protests.
Small numbers of voters turned out in the first hour of the balloting at polling stations, where army and police forces were deployed to head off potential clashes between opponents and supporters of the constitution, Egypt’s first since Hosni Mubarak’s ouster almost two years ago.
State media reported that the Islamist President Mohammad Mursi voted at a school in the eastern Cairo district of Heliopolis.
Mursi cast his ballot at a polling station near the presidential palace in Cairo, state television showed.
Mursi and his group, the Muslim Brotherhood, were at pains to rush through the charter amid an outcry from the mostly-secular opposition.
Polls are to remain open until 7pm (1700GMT). The rest of the country votes on December 22.
On the eve of the vote, stone-throwing clashes broke out between Islamists and opposition protesters in the Egyptian city of Alexandria, witnesses said.
The car of a cleric who had urged support of the referendum was set on fire and at least 10 people were injured, the official Middle East News Agency reported.
Cairo, Alexandria and eight other governorates are voting on Saturday, and the rest of the country a week later.
Tensions have been running high over the referendum, which is being held over two successive Saturdays, after weeks of protests and violence between the rival camps in Cairo that killed eight people and injured hundreds last week.
Both sides were holding further rallies in Cairo on Friday.
“Insistence on referendum in an explosive, polarized, chaotic & lawless environment is leading country to the brink,” opposition National Salvation Front leader Mohammad Al Baradei said on his Twitter feed.
The Front has said it could yet call a boycott if its “deep concern” over the referendum’s fairness turns out to be founded.
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.
Mursi has ordered Egypt’s military to help police maintain security until the results of the plebiscite are known. A total of 130,000 police and 120,000 soldiers will be deployed, interior ministry and military officials told AFP.
Polling in the referendum is being spread over two Saturdays because of a shortage of judges willing to provide the statutory supervision for the vote.
The Carter Center, which was the main international group to monitor previous elections since 2011, said Thursday it would not deploy a delegation to monitor the vote because of the authorities’ late release of regulations for accreditation of observers.