Huge crowds have gathered in the Egyptian capital, Cairo, for rival demonstrations in opposition and support of Islamist President Mohamed Morsi, on the first anniversary of his inauguration as Egypt's first freely elected leader.
In one of Sunday's rallies, thousands of secular and liberal opposition activists filled Cairo's Tahrir Square, waving Egyptian flags and chanting slogans demanding Morsi's resignation. They accuse him of trying to monopolize power in the hands of his Muslim Brotherhood movement and failing to fix the struggling Egyptian economy.
In another part of Cairo, Morsi's Islamist backers congregated around a mosque near the presidential palace. The opposition activists planned to march to the palace late Sunday. The streets of Cairo were unusually quiet for the start of the working week as many residents stayed home, fearing the prospect of a violent confrontation between the rival groups.
Organizers of both rallies said they want their followers to remain peaceful.
Morsi rejected the opposition demand he resign with three years remaining in his presidential term. In an interview with British newspaper The Guardian published Sunday, he said that if he gave in to the pressure, a new president could face similar opposition demands to quit after a "week or a month."
Morsi's supporters have vowed to defend him against what they see as opposition efforts to oust a democratically-elected leader. They accuse the opposition of trying to return Egypt to the era of longtime former autocratic president Hosni Mubarak, who was deposed in a popular pro-democracy uprising in 2011.
The Egyptian military deployed extra forces around the country to guard key installations including the Suez Canal. Street battles linked to the political tension killed at least seven people in the past week, among them an American student stabbed to death while photographing protests in Alexandria.
U.S. Deputy National Security Adviser Ben Rhodes said the United States has boosted security at its embassy and consulates in Egypt. Speaking Sunday, he also said the Obama administration has been in touch with Egyptian government officials and opposition figures to urge them to resolve their differences peacefully.
Organizers of Sunday's anti-Morsi protest said more than 22-million people signed a petition demanding the Islamist leader's resignation, almost double the number of people that voted for him in last year's presidential election. It was not possible to verify the petition figure independently.
President Morsi has offered to discuss reforms to the Egyptian constitution, drafted largely by Islamists last year and seen by many secular Egyptians as a threat to their way of life. But Egyptian opposition leaders have dismissed the president's gesture as too little, too late.