Egypt's ruling Islamists have claimed victory after the first round of a two-stage referendum on a controversial new constitution.
The new constitution, which is supported by the Islamists, has been bitterly contested by the country's secular-leaning opposition.
Cairo, Alexandria and eight other provinces voted in the first round of the referendum - the rest of Egypt goes to the polls on December 22.
The Islamist Muslim Brotherhood, which propelled Egypt's president Mohamed Morsi to power at elections in June, had representatives at almost all of polling booths used in the first round of voting.
One senior official from the Brotherhood told Reuters that unofficial results from the first round appeared to be in favour of the constitution.
"The referendum was 56.5 per cent for the 'yes' vote," he said.
Official results are not expected until after the next round of voting on December 22.
The official, who asked not to be identified, said the tally was based on counts from more than 99 per cent of the polling stations in this round.
One opposition official also said the vote appeared to have been in favour of the constitution, despite previous suggestions by the opposition that exit polls indicated the 'no' camp would win.
Another opposition official suggested that the vote would be "very close".
Mr Morsi and his backers say the constitution is vital to move Egypt's democratic transition forward.
The opposition says it is too Islamist and tramples on minority rights, including those of Christians - who make up 10 per cent of the population.