Egyptians on Saturday started to cast their ballots in a three-day referendum on constitutional reforms that could allow incumbent President Abdel Fattah al-Sisi to rule until 2030 and grant the head of state and the army more power.

Voting stations opened at 7 am GMT and are due to close 12 hours later as over 61 million people are called to vote.

Early in the morning, al-Sisi cast his ballot in Heliopolis, an eastern suburb of the capital, Cairo.

In Cairo’s district of Zamalek, dozens of people lined up in front of a ballot center before it had opened to take part in the process that had kicked off for Egyptians living abroad a day earlier.

The center was heavily secured by masked military members and the voters were organized by the security forces and secret services.

Earlier this week, Egypt's parliament approved the constitutional amendment.

The modification of Article 140 extends the duration of the presidential term from four to six years, an alteration that is supposed to enter into force the day following the end of the term of his predecessor – which means al-Sisi will remain in office till 2024 - and allows him to seek a third term.

The chamber also approved an amendment to Article 185 so that the head of state can appoint the heads of judicial institutions from among the seven oldest vice-presidents for a term of four years, or until retirement.

The constitutional reform that came five years after being approved is moving forward with the support of the overwhelming majority of the Parliament.

Only the opposition deputies, about 10 percent of the members of the chamber, have opposed the reform, which they believe goes against the achievements of the revolution that ended the regime of Hosni Mubarak in 2011 and led to the Constitution of 2014.

A group of 120 pro-government lawmakers from the 596-seat parliament signed a request on Feb. 3 to push for the constitutional reforms.

The request also included a proposal to restore the bicameral system that included the Consultative Council (best known as the Shura Council), which served as the upper house of the Egyptian parliament until it was dissolved by the same 2014 Constitution.

The campaign in favor of the amendments had kicked off with large banners on Cairo’s streets - including the central iconic square of Tahrir, the cradle of the 2011 and 2013 upraises - even before they were passed by the parliament.