Indonesia's government on Wednesday banned the local branch of Islamic group Hizb ut-Tahrir, rejecting criticism from rights groups that the move was undemocratic.
The government said it revoked the licence of Hizb ut-Tahrir Indonesia (HTI) because the group conducted activities that were against the state ideology.
The group, which calls for sharia and wants to unify all Muslims into a caliphate, has been operating for decades in Indonesia and has tens of thousands of followers.
"With HTI's legal status revoked, the group is therefore disbanded," the justice ministry said.
HTI said it would challenge the decision.
"This is a true form of abuse by the government against its own citizens," said its spokesman Ismail Yusanto.
The move came after president Joko Widodo issued a decree last week that strengthened the government's power to outlaw any group it deems to be opposed to the state ideology, or which spreads hatred against other races or religions.
The ideology, known as pancasila, officially encourages moderation and tolerance between different faiths.
Mr Widodo, a pluralist, has been under pressure to manage the growing influence of hardliners in the world's most populous Muslim-majority country.
Rights activists said the decree could stifle a broad range of democratic institutions.
Legal expert Refly Harun said it was the first time in the reform era that the government had disbanded an organisation without due process of law.
"The presidential decree is a blank cheque for the government to disband any group without due process of law," he said.
Indonesia was under dictator Suharto for more than three decades until the iron-fisted ruler was toppled in 1998 and democracy began to flourish in the country.