Egypt was bracing for a day of violence and protest as supporters and opponents of President Mohamed Morsi prepared for mass rallies following a night of clashes that left three people dead.
Rival demonstrators pitched tents and began sit-ins on Saturday to prepare for Sunday's rallies, a year to the day of Morsi's election. The demonstrations were planned after opponents called for Morsi's resignation and snap elections, which prompted pre-emptive demonstrations on Friday by the Muslim Brotherhood and its allies.
Morsi met the interior minister, Mohamed Ibrahim, and defence minister Abdel-Fattah el-Sisi Saturday to discuss plans to secure strategic locations, the state news agency MENA said.
Al Jazeera's Hoda Abdel Hamid, reporting from Cairo, said the anxiety was palpable.
"This country has been galvanised, focused on June 30. Listening to both sides, you can expect there to be some trouble. Both sides look at this as a matter of survival - the end game.
"They feel that whoever has the upper hand will be able to lead the country, even though there is no proof that will happen, that is the mindset at the moment. There is a lot of anxiety among Egyptians."
She added that while Sunday's protests were the focus, others feared about what will come afterwards.
"Everything is uncertain in this country. Many people are not so much worried about tomorrow but what happens next if president Morsi does stay in power - and every indication says that he will.
"There is no sign the opposition is willing to sit down with the president and there is no sign that the president has any concessions. No one is backing off," our correspondent said.
She said it remained to be seen what role the military would take in any trouble.
"The army has said it would not sit idle and watch Egypt slip into chaos. Now we don't know what threshold the military has, where it will say enough is enough," Abdel Hamid added.
The military has not directly intervened despite fatal attacks on Friday. The offices of the Freedom and Justice Party, the political arm of the Muslim Brotherhood from which Morsi hails, were set on fire in Alexandria and at Aga in Daqahliya. Its offices were stormed in Beheira.
Two people were killed in Alexandria, including an American student who was stabbed to death while taking pictures of the clashes, and an Egyptian journalist was killed in Suez Canal city.
Morsi's opponents, a collection of leftists, liberals, Christians and also deeply religious Muslims, accuse him of hijacking the revolution and concentrating power in the hands of Islamist groups.
Morsi supporters spent the night outside the Rabaa Al-Adawiya mosque in Cairo's Nasr City neighbourhood, where tens of thousands gathered on Friday to defend the legitimacy of Egypt's first freely elected president.
"It's not just about Morsi, it's about legitimacy and the state. We can't go backwards," said protester Kamal Ahmed Kamel.
|One year of Mohamed Morsi
Others called on the opposition to invest their energy in the political process.
"If it is that big tomorrow, why can't they use the ballot box and participate in parliamentary elections and get rid of Morsi that way?" Kamel asked.
In Tahrir Square, the epicentre of the 2011 revolt that toppled Hosni Mubarak, opponents also camped out and erected a large stage in preparation for what they call a "second revolution".
Some activists say they want Egypt governed by a presidential council and a national unity government.
"The Islamists have been in power for a year and they proved they failed at running the country," said activist Adel al-Amir.
"We will not allow a coup against the president," senior Brotherhood leader Mohamed al-Beltagui told a mass rally in Cairo.
The opposition National Salvation Front coalition has spurned Morsi's offer and renewed its demand for an election.
Sunday's protests have been called by Tamarod - Arabic for "rebellion" - a grassroots movement which says it now has 22 million signatures on a petition demanding Morsi's resignation and a snap election.