Police today used heavy tear gas to clear hundreds of supporters of Egypt's ousted Islamist president from Cairo's Tahrir Square shortly after they took over the plaza.
It was the first time in more than a year that Islamists entered the central square in significant numbers. The location has been the near-exclusive domain of liberal and secular protesters since shortly after now-deposed Mohammed Morsi took office in June 2012.
Police acted swiftly and appeared to surprise protesters, who quickly dispersed and took refuge in side streets. After a salvo of two dozen tear gas canisters, armoured police vans rushed to the square with sirens wailing. Later, six armoured personnel carriers arrived.
The square was the birthplace of the 2011 revolt that toppled long-time ruler Hosni Mubarak. That uprising was led by liberal and secular youth groups, whose differences with the Islamists began to surface later in 2011 over claims that Morsi's Brotherhood and its allies were more interested in their own political gains than pursuing the uprising's goals.
Today's Islamist protesters came from Cairo University, where they have been protesting over the death on Thursday of an engineering student at the hands of police. Non-Islamist students were also protesting at the death of the student today, but they restricted their demonstration to the area outside the Cairo University campus in the Giza district.
Jubilant Islamist students knelt and offered a prayer of thanks as their march drew closer to Tahrir, across the river Nile. Once there, they chanted slogans against the military and police and flashed the four-finger sign that commemorates the death of hundreds of Morsi supporters by security forces since a military coup ousted the Islamist president on July 3.
Morsi's supporters have been staging almost daily street protests to call for his reinstatement. Recently, groups that opposed Morsi have also taken to the streets to denounce the military-backed government's passage of a law that puts new restrictions on protests. It is seen by rights groups at home and abroad as a major setback to the country's transition to democratic rule.
Also today, Egyptian authorities ordered the release from police custody of prominent activist Ahmed Maher, founder of the revolutionary April 6 Movement, a main player in the 2011 uprising that toppled long-time ruler Hosni Mubarak.
But prosecutors extended by 15 days the detention of another figure from the 2011 uprising - Alaa Abdel-Fattah.
Both men face accusations related to intensely publicised clashes on Tuesday between police and demonstrators protesting against a clause in a new draft constitution enshrining the trial in some cases of civilians before military tribunals. Both Maher and Abdel-Fattah are accused of assaulting policemen during the protest in downtown Cairo.
Maher surrendered to police yesterday. Abdel-Fattah was arrested at his home two days earlier.