Egyptians began voting this morning in a constitutional referendum, the first ballot since the military overthrew Islamist president Mohammed Mursi.

The vote is thought likely to lead to a presidential bid by army chief General Abdel Fattah al-Sisi.

Few doubt that Egyptians, who staged mass protests against Mr Mursi's rule before his ouster, will turn out in big numbers and vote "yes" in the two-day referendum, a milestone on the army-backed government's political road map.

General Sisi ousted Mr Mursi, Egypt's first freely-elected head of state, in July.

General Sisi's Islamist foes see him as the mastermind of a coup that kindled the worst internal strife in Egypt's modern history and brought back what critics call a police state.

But many Egyptians are weary of the political upheaval that has gripped Egypt and shattered its economy since they rose up to topple autocrat Hosni Mubarak in 2011, and they view General Sisi as a decisive figure who can reinstate stability.

Analysts say the referendum is also turning out to be a vote on the popularity of a man whose image features on posters across Cairo.

If he runs for president, General Sisi is widely expected to win.

In the Nile Delta town of Tanta, about 40 women lined up at a polling station at a girl's primary school. About a dozen policemen and soldiers kept watch.

"The acceptance of this constitution will show that we had a glorious revolution on 30 June that was the will of the people implemented by the army," said Negla Hassan, a 30-year-old English teacher.

Egyptians who support the military takeover refer to it as a revolution, arguing that it represented the popular will because it followed mass protests against Mr Mursi's rule.

"We have removed the Brotherhood and we will live with stability and security with our police and our army. With Sisi at the head of our country, Egypt will be the mother of the world again," added Hassan.

Egypt's political transition may well keep stumbling.

Al-Qaeda-linked Islamist militants, which security officials say have ties to the Brotherhood, have stepped up attacks against security forces since Mr Mursi was ousted.

The Brotherhood has repeatedly said it is a peaceful movement and that it hoped street protests would bring down the government and its allies in the military.

But the severe security clampdown - hundreds of Islamists have been killed and thousands arrested - has taken the steam out of demonstrations.

Mr Mursi and many other top Brotherhood leaders have been arrested and are on trial.

One man was killed in clashes between security forces and supporters of Mr Mursi this morning, security sources said.

Mahmoud Sayed Gomaa, 25, was killed during a protest against the referendum near a polling station in the province of Bani Suef, south of Cairo.

An explosion was heard in Cairo just before voting was due to begin, security sources said this morning.

The blast occurred near a court complex in the district of Imbaba.

There were no early reports of casualties.