Riyadh: Saudi authorities arrested 13 men, who had planned terrorist attacks in the country, a security official said on Monday.

The 13 – all Saudi – were detained in a preemptive security operation earlier Monday, the spokesman for the Saudi state security agency added in a statement.

The suspects “arranged to carry out criminal acts targeting the country’s security and resources,” added the official without details. The statement named the 13 suspects.

The arrests come a day after Saudi security forces foiled an attempted attack on a police station in the province of Zulfi, north of the capital Riyadh. All the four assailants were killed on the scene.

Initial investigations identified all the four as Saudi nationals who were linked to the terrorist Daesh group, the state security agency said Monday. The four used a rest house owned by one of them in Zulfi as a “den” for planning their thwarted attack, the agency added.

The place was also used for making bombs and explosives.

In recent months, Saudi Arabia has mounted a high profile campaign against extremists.