Saudi authorities arrested 13 men, who had planned terrorist attacks in the country, a security official said on Monday, Saudi Press Agency (SPA) reported on Monday.
The spokesperson for the Saudi Presidency of State Security said explosive belts were found during a raid on the house of the Zulfi attackers.
Four heavily armed attackers were killed in a failed terrorist attack claimed by Daesh on an Interior Ministry building in Zulfi, north of Riyadh on Sunday.
The four terrorists that were killed belonged to Daesh. The Presidency of State Security released the identities of the four attackers: Abdullah Hamoud Al-Hamoud, Abdullah Ibrahim Al-Mansour, Samer Abdulaziz Al-Madid and Salman Abdulaziz Al-Madid.
Saudi authorities discovered a house in Al-Rayyan neighbourhood in Zulfi governorate, rented by Abdullah Al-Hamoud, one of the four perpetrators, where they found what resembled to be a factory for manufacturing explosives and explosive belts.
A total of five explosive belts were found, four of which were worn by the perpetrators, and another inside a car. The belts contain detonating keys and grenades with shrapnel-like screws.
Authorities also seized 64 homemade grenades, 61 pipe fittings, of which nine were being processed as pipe bombs, three mobile phones, three pressure cookers ready for detonation, two Kalashnikov machine guns, six pistols, and other various weapons.
They also found four bags (74,900 kg) containing organic fertilizers, along with sets of laboratory glass containers, a number of plastic containers, a package of liquid chemical containers, sulfur-fibre cartons, a homemade explosive detonator and a set of screws that were equipped with shrapnel.
Authorities also seized a set of ATM cards, two national identity cards, SR 228, a number of publications and CD-ROMs with content related to the terrorist organization.
The Presidency of State Security said it is continuing to follow up with terrorist elements that threaten the security and stability of the Kingdom.