Saudi Arabia has arrested 431 men suspected of belonging to Islamic State cells .
The interior ministry said the arrests foiled attacks on mosques, security forces and a diplomatic mission.
"Four-hundred and thirty one people have been arrested by the Saudi authorities to date (most of them citizens). Saudi authorities are still working to arrest any other people related to this group," an Interior Ministry spokesman said.
It is not known when the men were detained, but previous announcements of arrests suggest the operation has been ongoing for several months.
A string of deadly attacks carried out by followers of the ultra-hardline militant group has fuelled concerns about a growing threat of militancy in the country.
Islamic State has said its priority target is the Arabian peninsula and, in particular,Saudi Arabia.