Vote counting was underway in Egypt after two days of polling ended Thursday in a landmark presidential election which pitted stability against the ideals of the uprising that ended Hosni Mubarak's rule.
Just hours after polling stations closed at 9:00 pm (1900 GMT), the powerful Muslim Brotherhood -- using their formidable nationwide network to tally votes -- predicted a win for their candidate, Mohammed Mursi.
"I am confident that as first indications show, our candidate is leading," Essam al-Erian, vice chairman of the Islamist group's Freedom and Justice Party, told reporters, based on results from 236 out of 13,000 polling stations.
After decades of pre-determined results, for the first time the outcome of the vote in the Arab world's most populous nation was wide open, and may well force a second round runoff vote between the two frontrunners next month.
"Before the revolution, I never voted, because it was not useful. Since then, I have voted in every election because it's my right and my duty," said Ahmed Badreddine, 37, at a polling station in Cairo's Giza neighbourhood.
Turnout appeared to vary widely across the country, with long queues outside some polling stations and scant participation in others.
The official body supervising the election estimated that around 50 percent of eligible voters had cast their ballot.
Around 50 million voters were called to choose from 12 candidates, with the opinion poll frontrunners divided between Islamists, who say they will champion the uprising's goals, and Mubarak-era ministers.
Among the contenders is former foreign minister and Arab League chief Amr Mussa, seen as an experienced politician and diplomat. But like Ahmed Shafiq, Mubarak's last prime minister, he is accused of ties with the old regime.
The powerful Muslim Brotherhood's candidate, Mursi, faces competition from Abdel Moneim Abul Fotouh, a former member of the Islamist movement who portrays himself as a consensus choice.
Pollsters said the large number of undecided voters made the result of the first round of polling extremely difficult to predict. with a second round vote a distinct possibility.
At a school in the upmarket Cairo neighbourhood of Heliopolis, with the dome of Mubarak's former presidential palace visible a few hundred metres (yards) away, hundreds of women braved the heat to queue to vote.
Noha Hamdy, 27, said it was a pleasant novelty to be voting in an election where the outcome is not predetermined.
"We go to an election not knowing who will win. I never voted before because the winner was always known in advance," she said. "This time I feel who I vote for, even if he doesn't win, will make a difference."
The next president will inherit a struggling economy, deteriorating security and the challenge of uniting a nation divided by the uprising and its sometimes deadly aftermath, but his powers are yet to be defined by a new constitution.
"The big challenge for the president will be to attract foreign investors and boost tourism," to "restore the balance of payments" and "restore the reserve" currency in the central bank, which has dropped by half in the past year, Mahmoud Abdel Fadil, a Cairo University economics professor, told AFP.
To do that, the new president will have to "re-establish political stability and assure a level of total security. Confidence must be restored," he added.
The election seals a tumultuous military-led transition from autocratic rule marked by political upheaval and bloodshed, but which also witnessed democratic parliamentary elections that saw Islamist groups score a crushing victory.
Ballot boxes from Wednesday's first day of voting were kept overnight in polling stations after being sealed with wax by electoral commission officials and left under military and police protection.
The Supreme Council of the Armed Forces, in power since Mubarak's ouster, has vowed to restore civilian rule by the end of June, after a new president is in place, but many fear its withdrawal from politics will be just an illusion.
The army, with its vast and opaque economic power, wants to keep its budget a secret by remaining exempt from parliamentary scrutiny, maintain control of military-related legislation and secure immunity from prosecution.
Mubarak, 84 and ailing, is being held in a military hospital on the outskirts of Cairo where he awaits the verdict of his murder trial on June 2.
The former strongman, ousted in a popular uprising last year, is accused of involvement in the killing of some 850 protesters during the uprising and of corruption.