RABAT: Thousands of Moroccans led by an Islamist movement rallied in the capital Rabat Sunday in a massive show of support for protests against corruption and official abuses in a northern region that have tested authorities for weeks. Chanting against “ruling mafia” and carrying portraits of detained activists, protesters packed Rabat’s Bab El Hed area and marched toward the Parliament, with most from the Adl Wal Ihsan (Justice and Spirituality) Islamist movement.

Political unrest is rare in the North African kingdom but protests around northern city Al-Hoceima have been on the rise since October.

The participation of Justice and Spirituality is significant. A major player in the 2011 protests, the movement is banned from formal politics, but is the only opposition group able to mobilize on a massive scale. “We came out to protest about the social reality in Morocco,” said Lamia, a school teacher who came from the northern city of Tetouan to the Rabat rally. “We’re here in solidarity with Al-Hoceima, to demand dignity.”

An Interior Ministry source said between 12,000 and 15,000 people took part in Sunday’s protest which was organized by several organizations. It was the most significant political rally in Rabat since the 2011 unrest and smaller leftist groups and labor unions, as well as some parliamentary opposition parties, also participated. Some chanted slogans, including: “You’re corruption is starting to stink.”

The northern protests erupted in October in Al-Hoceima after fishmonger Mouhcine Fikri was crushed inside a garbage truck while trying to salvage his fish that had been confiscated by police.

Some of the anger in the Al-Hoceima protests has been directed at “Makhzen,” the royal governing establishment, but the unrest has not been aimed at the king. Morocco has a deeply rooted monarchy, the Muslim world’s longest-serving dynasty.

But tensions in Al-Hoceima and the Rif region have been rising since the arrest of the protest movement’s leader Nasser Zefzafi on charges of threatening national security. Demonstrators have rallied nightly in Al-Hoceima and the nearby town of Imzouren since his arrest.

Sunday’s demonstration in Rabat came after an official and an activist said police had detained four more people in the Rif at the weekend.

Over the past two weeks authorities in the North African country have arrested dozens of people in a crackdown on Al-Hirak al-Shaabi or “Popular Movement” protests in the Rif port of Al-Hoceima.

The unrest is testing nerves in a kingdom that presents itself as a model for stability and gradual reform, as well as a safe haven for foreign investment in a region affected by militant violence.