It said the group had "ideological and financial links" with al-Qaeda and other international terrorist groups.
Moroccan security officials say police have broken up more than 50 Islamist cells, and arrested more than 3,000 people since suicide bombings in Casablanca in 2003.
Last August the government said it had broken up a cell that was planning to declare a holy war in the northeast of the North African country, attack tourist sites and kill people who symbolise the state.
Human rights
Rights groups say hundreds of the people arrested since 2003 have faced ill-treatment or unfair trials, something the government denies.
Its statement said those arrested in the latest round-up will be brought before judicial authorities, in line with Morocco's anti-terrorist laws.
The arrests were "transparent and in respect of the law", Nabil Benabdallah, a government spokesman, said.