Egyptians are going to the polls in the second round of presidential elections, the first since Hosni Mubarak was forced to step down by an uprising in February last year.
Mohammed Mursi, head of the Muslim Brotherhood's Freedom and Justice Party, is pitted against Ahmed Shafiq, Mubarak's last prime minister.
Both men have vowed to restore stability and security to Egypt.
The country's ruling Supreme Council of the Armed Forces (SCAF) is due to hand over to the new president on July 1.
But the run-up to the election, which will continue on Sunday, has been marred in controversy after the Supreme Constitutional Court dissolved parliament on Thursday.
The Court ruled that the law governing last year's parliamentary elections was unconstitutional.
Mursi's Freedom and Justice Party controlled nearly half of the seats in the 508-member People's Assembly, which has been in session for just over four months.
The ruling was condemned as a "coup" by a number of scholars and politicians.
"This series of measures shows that the Supreme Council of the Armed Forces, the head of the counter-revolution, is adamant to bring back the old regime and the presidential elections are merely a show," six of Egypt's parties and movements said in a statement, according to the BBC.
U.S. Secretary of State Hillary Clinton said on Friday Washington expected the SCAF to fully transfer power to a democratically elected civilian administration as planned.
"There can be no going back on the democratic transition called for by the Egyptian people," Clinton told reporters in Washington.
