Several thousand Islamist supporters of deposed Egyptian President Mohammed Morsi marched through downtown Cairo on Monday calling for his reinstatement and denouncing the army general who led his overthrew.
The protest took place as international envoys stepped up talks with leaders of both sides of the crisis in a bid to find a political solution and avert further bloodshed.
Marchers chanted "Morsi, Morsi" and "We are not terrorists", and waved picture of the ousted leader.
Some sprayed graffiti on walls and statues calling army chief General Abdel Fattah al-Sisi, who led the overthrow of Morsi on July 3, a murderer and a traitor.
The protesters, nearly all men, marched 10 abreast and stretched back several blocks. Security forces made no immediate attempt to disperse a crowd estimated by reporters at several thousand strong.
The protest showed tension is still running dangerously high in Egypt more than a month after Morsi's removal despite the international mediation effort by the United States, the European Union, Qatar and the United Arab Emirates.
Morsi became Egypt's first freely-elected president in June 2012, 16 months after the overthrow of strongman Hosni Mubarak, who had ruled for nearly 30 years.
But fears that he was trying to establish an Islamist autocracy coupled with a failure to ease economic hardships afflicting most of its 84 million people led to huge street demonstrations on June 30, triggering the army move.
The international mediation effort has so far helped to contain further conflict between Morsi's backers and the security forces but has yet to broker a solution.
Thousands of Morsi supporters remain camped out in two Cairo sit-ins, which the government has declared a threat to national security and pledged to disperse. The army-backed interim government said on Sunday it would give mediation a chance but warned that time was limited.
Almost 300 people have been killed in political violence since Morsi's overthrow, including 80 shot dead by security forces in a single incident on July 27. Morsi and much of the leadership of his Muslim Brotherhood are in custody.
Monday's marchers halted outside the office of the public prosecutor, whom they denounced as politically-biased. In anti-Morsi demonstrations at the same place before his overthrow, protesters had demanded the removal of his appointee to the office, accusing him of ordering arrests of his opponents.
One protester, Mohamed Mustafa, 28, a Cairo University student, told Reuters: "Our president is Mohamed Morsi. He will be back. He will complete his presidency. Day after day we stay in Cairo. This is fight is not over. Morsi will return."
Mahmoud Isuafi, a businessman from the Nile Delta city of Mansoura, held a Koran in one hand and a picture of Morsi in the other.
"The military came and stole our country, they stole everything," he said. "I want democracy. Where is my vote? I can no longer elect my leader so I protest instead."
In the early hours of Monday, the international envoys visited senior Muslim Brotherhood official Khairat El-Shater at Tora prison, south of Cairo, state news agency MENA reported.
The delegation included U.S. Deputy Secretary of State William Burns and European Union envoy Bernardino Leon and were accompanied by members of the armed forces, according to Al Masry Al Youm newspaper.
Shater is deputy leader of the group that propelled Morsi to office last year. Seen as the Brotherhood's political strategist, he was arrested after Morsi's downfall on charges of inciting violence.
Shater told the envoys he would only hold talks with them in the presence of Morsi because he was "the legitimate president", the newspaper reported, citing a senior security source.
The military has laid out a plan that could see a new head of state elected in roughly nine months. The Brotherhood, an Islamist movement that spent decades in the shadows before Mubarak's downfall, says it wants nothing to do with it.
However, diplomats say the Brotherhood knows Morsi will not return as president and wants a face-saving formula for him to step down that guarantees it a stake in the political future.
On Sunday, a Cairo court said the Brotherhood's leader and two other officials including Shater would go on trial in three weeks' time for crimes including incitement to murder during protests in the days before Morsi was toppled.
During a meeting with Burns and Leon on Saturday, a pro-Morsi delegation said they were willing to negotiate with politicians that backed Morsi's overthrow.
But they are also seeking the restoration of a constitution suspended when Morsi was deposed and want the military, together with General al-Sisi, out of politics.
Morsi is being held at an undisclosed location and facing an investigation into accusations including murder.
Two U.S. senators, Republicans Lindsey Graham and John McCain, were heading to Cairo on Monday at President Barack Obama's request to meet members of the new government and the opposition.
Before leaving, Graham said the Egyptian military must back out of politics quickly or risk a cut of the e1.5 billion in aid it receives from Washington each year.
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