Moroccan authorities arrested a French national suspected of involvement in the May 16th suicide bombings in Casablanca that killed 43 people, the official MAP news agency said.
The agency said Mr Robert Richard Antoine Pierre, who used the aliases Lhaj and Abu Abderrahmane suggesting that he converted to the Islamic faith, was arrested in the northern city of Tangiers.
Thirty-one people were killed in the attacks along with 12 suicide bombers who almost simultaneously targeted five sites in the sprawling city, including a Spanish restaurant, a five-star hotel and a Jewish community centre.
Morocco, a staunch US ally, said the suicide bombers had links with international terrorism and that details would be given once investigations are complete.
Authorities said they have charged at least 30 men in connection with the attacks which have been blamed on a small Islamic group based in a poor Casablanca neighbourhood.
The alleged mastermind of the bombings died in police custody last week, two days after his arrest, from chronic heart and liver disease, they said.