Moroccan police have clashed with protesters demanding the release of a prominent leader.

It came after anti-government demonstrators by the hundreds started throwing rocks and trash at police in Imzouren, a town 450 kilometers northeast of the Moroccan capital, Rabat.

Police fired water cannon to disperse the crowd who were protesting against corruption, repression and unemployment.

Last week, Nasser Zefzafi, who emerged as the leader of the protesters’ Popular Movement, was arrested and charged with threatening national security.

Most shops were shuttered in the port city of al-Hoceima – where Zefzafi was apprehended after three days on the run.

Protesters also took to the streets of Hoceima on Friday, chanting slogans including “we are all Zefzafi”, while holding pictures of him.

Hoceima has been witnessing demonstrations since last year, when a local fisherman was killed in a refuse truck as he was trying to retrieve his merchandise confiscated by police.

The incident happened in October 2016, as a garbage compactor he had climbed into started operating.

Morocco’s government said 40 people have been arrested since last Friday.

“We fear this wave of arrests may be a deliberate attempt to punish protesters in the Rif for months of peaceful dissent. It is essential that the Moroccan authorities respect the right to freedom of expression and assembly,” said Heba Morayef, North Africa Research Director for Amnesty International.