Clashes erupted in various cities between pro-Morsi protesters and security forces or groups of locals who opposed the protests. The clashes were later dispersed by police and military forces.
Today's protests were called for by the Muslim Brotherhood-led National Alliance to Support Legitimacy under the slogan "the youth are the pillar of the revolution."
The alliance has called for a week of rallies starting today, to coincide with the first week of the new academic year.
A separate rally in the Cairo district of Heliopolis also took place today. Protesters numbering in hundreds headed to the presidential palace chanting anti-army and anti-police slogans.
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The rally reached to El-Merghany Street and did not advance as security forces had blocked off all routes to the palace.
In Alexandria, clashes also erupted between hundreds of pro-Morsi protesters and groups of locals in the Camp Shiraz area, and later spread to other districts including Sidi Gaber and Mostafa Kamel.
According to the National Alliance to Support Legitimacy, 18 pro-Morsi protesters were injured today, while 30 were arrested.
The turnout at the day's demonstrations was markedly lower than in previous weeks. A wave of arrests targeting senior Brotherhood figures has impacted the ability of the group to mobilise supporters.
Egypt's interim government last week extended a state of emergency, in force since mid-August, by another two months amid continued political unrest.
Hundreds of people had been killed when police cleared two pro-Morsi protest camps in Cairo and Giza on 14 August, triggering wide-spread street violence.