Thousands protested in Umm al-Fahm on Saturday afternoon in solidarity with the northern branch of the Islamic Movement following the decision to outlaw it.
The protest was organized by the High Follow-Up Committee for Arab Citizens of Israel. Large police forces were deployed to the entrance of the city to secure the protest.
Among the protesters were many Arab MKs and hundreds of Arab leaders condemning the decision to ban the group and calling on the Arab public in Israel to continue and expand the protest until Israel backtracks on its decision.
"With our spirit and blood we shall redeem you, al-Aqsa," the protesters called out. "We will not shut up. We're all with the Islamic Movement. Outlaw the racists."
Protesters said they were "proud of the Islamic Movement" and waved signs saying "The decision hurts all Arab citizens."
Police did not say how many people attended the protest, but a Reuters photographer said there were about 15,000 demonstrators in what was one of the largest Arab rallies in Israel in recent years.
The Islamic Movement's northern branch does not, unlike its southern counterpart, recognize Israel's legitimacy. It runs its own educational and religious services and has been at the forefront of protests against government policies toward Israeli Arabs and the Palestinians. The group says its activities are lawful.
But Israel says the movement has encouraged Palestinian assaults on Israelis by falsely accusing the government of trying to erode Muslim control of Jerusalem's al-Aqsa mosque complex, Islam's third holiest site and the most sacred site in Judaism.
"The entire Arab leadership opposes the outlawing of the Islamic Movement, and it shows in today's protest," said MK Jamal Zahalka of the Joint Arab List. "This is a protest of unity. We won't allow the Islamic Movement to be isolated. Hurting the movement is hurting the entire Arab public, it is a provocation against us. Instead of saying thank you that we're all participating in a non-violent legal struggle, they outlaw the movement and push parts of our public to illegal activity. The repercussions could be dangerous. This is not just wickedness, but complete stupidity."
"We're very angry about this strange decision," said Muhammed Mahmaim from Umm al-Fahm. "The Follow-Up Committee and all of the other groups should expand the struggle and not stop. Our reaction should be stronger, not just protest and go home. This decision is a message to us all. Yesterday they outlawed the northern branch, soon they'll target us too, so there is no way we remain quiet over a move like this. It is our duty to think of ways to force the racist government to cancel this irresponsible decision."
Another protester also called to take harsher steps. "I think it's time to block roads and protest. The government will be held responsible for everything that happens. This kind of decision can set the region on fire. We don't have another way. If Netanyahu and his radical government continue with such steps, our response will be very strong. This time we won't give up and we're willing to sacrifice our life for the Islamic Movement," he said.
Israel's Security Cabinet decided some ten days ago to declare the northern branch of the Islamic Movement as an unlawful organization. Meaning, anyone who continues activity as part of the Islamic Movement will be considered a criminal. Under certain conditions, the state could seize funds and property that belong to the movement. Shin Bet and Police could now arrest any activists or supporters of the northern branch.
There were some dissenting opinions in Shin Bet circles regarding the move, raising concerns that the decision might lead to anger and an eruption of violence, and that it could cause the members of the northern branch to move their activities underground, which could make them tougher to track.
Reuters contributed to this report.