Ex-army chief Abdel Fattah al-Sisi won 96.9 per cent of votes in Egypt’s presidential election, the electoral commission says, almost a year after he overthrew elected Islamist leader Mohamed Morsi.

Turnout in last week’s election, hastily extended to three days amid fears of low turnout, was 47.45 per cent, said commission chief Anwar Rashad al-Asi.

Sisi’s rival Hamdeen Sabbahi won just three per cent of the vote, excluding spoiled ballots.

Sisi’s lopsided victory had been certain, with many lauding the retired field marshal as a hero for ending Morsi’s divisive rule in July.

Yet the lower-than-expected turnout signalled that a wide segment of the population was apathetic or boycotted the election.

The Muslim Brotherhood, crushed by a massive crackdown following Morsi’s overthrow and detention, had boycotted the vote.

Some journalists and government employees erupted in applause and began dancing as the final results were announced at a press conference on Tuesday.

Saudi Arabia’s King Abdullah, who opposed the Muslim Brotherhood, immediately called for a donors conference to help Egypt after the results were announced.

With an economy hammered by years of unrest, Sisi urged Egyptians to “work to return security to this nation,” in a television address after the final results were declared.

“The future is a blank page, and it is in our hands to fill with what we want … bread, freedom, human dignity, social justice,” he said.

Sisi’s appeal mirrored the slogan of the 2011 uprising that overthrew dictator Hosni Mubarak, as his critics warned the retired field marshal could impose an even more repressive government.

In Cairo’s Tahrir Square, where protesters had battled police three years ago in an uprising to overthrow dictator Mubarak, several thousand Sisi supporters celebrated and set off fire works.

“We are celebrating the hope of restoring stability and security,” said Naela Mahmoud, a school principal.

But her daughter, Hala Abu Fadl, 29, recalled the past violence in the iconic square, once synonymous with rebellion against Mubarak and the army, which took over between his overthrow and Morsi’s election in June 2012.

“Celebrating here is difficult,” she said, pointing to a mural depicting a slain protester, at the entrance of a street where activists clashed with police and soldiers in 2011.

“I voted for Sisi for stability, but I fear a crackdown on freedoms,” she said.

Sisi will take office by the end of the month, with interim president Adly Mansour likely returning to his previous post as chief judge of the constitutional court.

Sisi, appointed by Morsi as defence minister before he overthrew him, has suggested he would not tolerate protests as he moved to restore the battered economy.