PARIS - French prosecutors on Thursday put 10 members of a radical far-right movement under formal investigation on charges of plotting assaults against Muslims, according to local reports.

Nine men and one woman were accused of "belonging to a criminal association in relation to a terrorist undertaking," news channel BFMTV reported.

Four of the suspects will stay in custody pending trial, while two are still waiting for a judge to decide on their case and four others were released, it added.

Last weekend, anti-terrorism units arrested the suspects linked to the ultra-right group Action des Forces Operationnelles (Operational Forces Action) who were believed to be preparing attacks against Muslims chosen at random.

Thirty-six weapons and homemade grenades were found during police raids in the Paris region, the Mediterranean island of Corsica and in the central and southwestern French cities on the weekend.

"The group was trying to recruit new members and extend its reach by structuring itself at the regional level," the report said.

The suspects were aged 32 to 69. Among them was a retired police officer. All were previously unknown to police.