Saudi authorities claim to have broken up an organisation linked to the Islamic State group arresting 431 of its members, mostly Saudis.
Authorities have "managed over the past few weeks to destroy an organisation made of a cluster of cells, which is linked to the terrorist Daesh organisation," the interior ministry said on Saturday, using the Arabic acronym for IS.
Network members were engaged in a "plot managed from areas of unrest abroad, with the aim of sowing sectarian sedition and spreading chaos," the ministry said.
The cells were involved in several attacks and plots, including the deadly suicide bombings that hit Shi'ite mosques in the kingdom's Eastern Province, it said.
The Islamic State, which considers Shi'ites heretics, has claimed responsibility for the attacks.
IS controls swathes of neighbouring Iraq and Syria, and has claimed widespread abuses including the beheading of foreign hostages.
Saudi Arabia and its Sunni Gulf neighbours last year joined a US-led military coalition bombing IS in Syria, raising concerns about possible retaliation in the kingdom.