Several thousand people took to the streets of Morocco's northern Rif region to demand the release of the leader of a protest movement.
Nasser Zefzafi, 39, who had been on the run since Friday, was taken into custody on Monday "along with other individuals" and transferred to Casablanca. His arrest was ordered after he allegedly interrupted a preacher at a mosque on Friday and called for further demonstrations.
Protestors came out near the centre of the northern city of Al Hoceima for a fifth straight night on Tuesday, shouting slogans including "we are all Zefzafi" and "end militarisation".
The protesters, including women and children, held aloft hundreds of pictures of Zefzafi, who has emerged as the leader of the grassroots, "Popular Movement."
Others held up berber flags, the symbol of a strongly-felt regional identity in an area many claim has long been neglected by central authorities.
One brandished a sign saying "Free the prisoners or put us all in prison!"
Anti-riot police attempted to disperse the protesters but pulled back following a tense but non-violent standoff.
The Rif region has been shaken by social unrest since the death of a fishmonger in October.
The 31-year-old Mouchcine Fikri was crushed in a rubbish truck as he protested against the seizure of swordfish caught out of season.
Calls for justice for Fikri evolved into a grassroots movement demanding jobs and economic development, with Zefzafi, himself unemployed, emerging as the leader of the Al-Hirak al-Shaabi, or Popular Movement, based largely in Al Hoceima.
Images that appeared on social media showed similar protests took place in the neighbouring town of Imzouren, with a strong police presence.
Smaller protests were also held in the capital Rabat and Casablanca but were broken up by police, Moroccan media reported.
According to officials, 40 people were arrested by Monday evening in connection with the disturbance of Al Hoceima. Human rights groups have given higher figures, however.