Nine members of the cell were arrested in towns across Morocco, including Kenitra near the capital Rabat, the interior ministry said in a statement.
The ministry said the suspects were "at an advanced stage of preparing attacks on sensitive sites" in the country.
Signup to our newsletter and follow us on Facebook and Twitter!
"The suspects have revealed that they had received instructions from Daesh to target sensitive sites in the kingdom with explosives," it said, using an Arabic synonym for IS.
The ministry said they had ties to Moroccan jihadists fighting with IS in Syria and Libya, and that arms and ammunition were seized during the arrests, mostly in Kenitra.
It was the latest in a string of announcements over past weeks of IS-linked cells being busted in Morocco and of the arrests of suspected recruitment agents for the jihadists.