Supporters of ousted president Mohamed Morsi clashed with anti-Morsi protesters who have been holding a sit-in in Tahrir Square on Monday afternoon.
The pro-Morsi demonstrators approached Tahrir Square after holding a protest rally at the US embassy in a few blocks away.
Earlier in the day, Egypt's armed forces have blocked all routes to the defence ministry in Cairo's Abbasiya district on Monday, preventing a march by thousands of deposed president Mohamed Morsi supporters from reaching the building.
Morsi supporters continue their call for Morsi's reinstatement, protesting against what they say was a military coup against Egypt's first democratically-elected leader.
Limited scuffles broke out between pro-Morsi protesters and passersbys who oppose the march.
Hundreds of pro-Morsi protesters have gathered at the High Court on Ramses Street, a main road in downtown Cairo. They were joined by another march by several thousands of Morsi supporters moving from the Engineers' Syndicate building on Ramses.
The rally has obstructed traffic movement on Ramses Street and the nearby 26 July Street.
On Sunday, the army also stopped two women's marches, protesting the killing of at least three female protesters in Friday's Mansoura clashes, from reaching their destinations in Cairo. One was headed to the defence ministry while the other to the National Council for Human Rights in Giza.
Egypt's army deposed Morsi on 3 July following mass nationwide protests against him. Head of High Constitutional Court Adly Mansour was sworn in as interim president the next day.
The National Alliance for Legitimacy Support, a coalition of Islamist parties led by the Muslim Brotherhood from which Morsi hails, has been staging protests and sit-ins across Cairo and several governorates calling for Morsi's reinstatement.
