Amnesty International said in March it had evidence to suggest at least 120 people were briefly detained after security forces beat protesters during a sit-in at the main square. Riot police prevented other demonstrations from reaching the city center in Casablanca.
The violence followed an announcement from Moroccan King Mohamed VI that the government was willing to protect political freedoms and undertake reforms to address protesters' demands.
The February 20 movement, a group backed by Islamist movement Adl wan Ihsan, is leading protests against the Moroccan monarchy. They are calling for more employment opportunities and an end to government corruption, al-Jazeera reports. Adl wan Ihsan is banned from Moroccan politics.
The March reforms announced by Mohamed VI are the first in 15 years.
The report from the Arab broadcaster notes much of the demonstrators come from the country's working class. Protests were described as relatively peaceful.