Egypt's unrest comes after the military ousted President Mohammed Morsi, an Islamist, from power after several days of mass demonstrations against him.
Here are some key events from more than two years of turmoil and transition in Egypt:
Jan. 25-Feb. 11, 2011 -- Egyptians stage nationwide demonstrations against the rule of President Hosni Mubarak. Hundreds of protesters are killed as Mubarak and his allies try to crush the uprising.
Feb. 11 -- Mubarak steps down and turns power over to the military. The military dissolves parliament and suspends the constitution, meeting two key demands of protesters.
March 19 -- In the first post-Mubarak vote, Egyptians cast ballots on constitutional amendments sponsored by the military. The measures are overwhelmingly approved.
Oct. 9 -- Troops crush a protest by Christians in Cairo over a church attack, killing more than 25 protesters.
Nov. 28, 2011-Feb 15, 2012 -- Egypt holds multistage, weekslong parliamentary elections. In the lawmaking lower house, the Muslim Brotherhood wins nearly half the seats, and ultraconservative Salafis take another quarter. The remainder goes to liberal, independent and secular politicians. In the largely powerless upper house, Islamists take nearly 90 percent of the seats.
May 23-24, 2012 -- The first round of voting in presidential elections has a field of 13 candidates. Morsi and Ahmed Shafiq, the last prime minister under Mubarak, emerge as the top two finishers, to face each other in a runoff.
June 14 -- The Supreme Constitutional Court orders the dissolving of the lower house of parliament.
June 16-17 -- Egyptians vote in the presidential runoff between Morsi and Shafiq. Morsi wins with 51.7 percent of the vote.
June 30 -- Morsi takes his oath of office.
Aug. 12 -- Morsi orders the retirement of the top Mubarak-era leadership of the military.
Nov. 19 -- Members of liberal parties and representatives of Egypt's churches withdraw from the 100-member assembly writing the constitution, protesting attempts by Islamists to impose their will.
Nov. 22 -- Morsi unilaterally decrees greater powers for himself, giving his decisions immunity from judicial review and barring the courts from dissolving the constituent assembly and the upper house of parliament. The move sparks days of protests.
Nov. 30 --Islamists in the constituent assembly rush to complete the draft of the constitution. Morsi sets a Dec. 15 date for a referendum.
Dec. 4 -- More than 100,000 protesters march on the presidential palace, demanding the cancellation of the referendum and the writing of a new constitution. The next day, Islamists attack an anti-Morsi sit-in, sparking street battles that leave at least 10 dead.
Dec. 15, Dec. 22 -- In the two-round referendum, Egyptians approve the constitution, with 63.8 percent voting in favor. Turnout is low.
Dec. 29 -- The Egyptian Central Bank announces that foreign reserves -- drained to $15 billion from $36 billion in 2010 -- have fallen to a "critical minimum" and tries to stop a sharp slide in the value of the Egyptian pound. It now stands at just more than 7 to the dollar, compared to 5.5 to the dollar in 2010.
Jan. 25, 2013 -- Hundreds of thousands hold protests against Morsi on the 2-year anniversary of the start of the revolt against Mubarak, and clashes erupt in many places.
Feb.-March 2013 -- Protests rage in Port Said and other cities for weeks, with dozens more dying in clashes.
April 7 -- A Muslim mob attacks the main cathedral of the Coptic Orthodox Church as Christians hold a funeral and protest there over four Christians killed in sectarian violence the day before. Pope Tawadros II publicly blames Morsi for failing to protect the building.
May 7 -- Morsi reshuffles his Cabinet. Officials say the changes aim to finalize long-stalled negotiations with the International Monetary Fund for a crucial $4.8 billion loan, which requires reductions to fuel and food subsidies. A deal on the loan has still not been reached.
June 23 -- A mob beats to death four Egyptian Shiites in a village on the outskirts of Cairo.
June 30 -- Millions of Egyptians demonstrate, calling for Morsi to step down. Eight people are killed in clashes outside the Muslim Brotherhood's Cairo headquarters.
July 1 -- Large-scale demonstrations continue, and Egypt's powerful military gives the president and the opposition 48 hours to resolve their disputes, or it will impose its own solution.
July 2 -- Military officials disclose main details of the army's plan if no agreement is reached: replacing Morsi with an interim administration, canceling the Islamist-based constitution and calling elections in a year. Morsi delivers a late-night speech in which he pledges to defend his legitimacy and vows not to step down.
July 3 -- Egypt's military chief announces that Morsi has been deposed, to be replaced by the Chief Justice of the Supreme Constitutional Court until new presidential elections. No time frame is given. Muslim Brotherhood leaders are arrested.
July 4 -- Supreme Constitutional Court Chief Justice Mansour Adly is sworn in as Egypt's interim president.
July 5 -- Adly dissolves the Islamist-dominated upper house of parliament as soldiers open fire on mostly Islamist protesters in Cairo demanding restoration of Morsi, killing at least one person.