The fresh protests were organised by the February 20 Movement, which has organised months of demonstrations calling for reforms in the Arab world’s oldest reigning monarchy and denounced a new constitution as window-dressing.
About 8 000 protesters chanted slogans denouncing corruption and calling for more equality in Casablanca’s Oulfa neighbourhood, an AFP correspondent reported.
The February 20 Movement includes the Justice and Charity group – an Islamist organisation that is officially banned but tolerated by the authorities – as well as leftist militants and independent cyber-activists.
In the capital Rabat, about a thousand protesters also gathered on Bab El Had square in the city centre.
They were met by a handful of counter-demonstrators waving portraits of King Mohammed VI but no incident was reported.
Demonstrations were also scheduled to take place in the city of Tangiers later in the evening.
A July 01 referendum on a new constitution curbing the king’s near absolute powers was overwhelmingly adopted.
But that result has failed to quell calls for more radical political reform. Pro-democracy activists inspired by similar movements elsewhere in the Arab world have vowed to continue their protests.