Riyadh: Saudi authorities on Saturday announced that they have broken up an organisation linked to the Islamic State group and have so far arrested 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, 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 deadly suicide bombings at Shiite mosques in the kingdom's Eastern Province, it said.
The ministry said that authorities foiled attacks plotted during the Muslim fasting month of Ramadan, including a bombing at a mosque belonging to security forces in Riyadh and Shiite mosques in Eastern Province.
The group also plotted to attack a diplomatic mission, the statement said without elaborating.
Among those detained are 144 people accused of supporting the network by "spreading the deviant ideology on the internet and recruiting new members".
The Islamic State group, which considers Shiites to be heretics, claimed responsibility for the mosque attacks.
IS controls swathes of neighbouring Iraq and Syria, and has claimed widespread abuses including the beheading of foreign hostages.
It has expanded its operations in the region, also claiming an unprecedented attack on a Shiite mosque in Kuwait, and several attacks in Yemen.
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.
Interior Minister Crown Prince Mohammed bin Nayef said after a deadly mosque attack in May that Saudi Arabia's security remains "under control".
"Incidents such as this will not destabilise us. We have been through bigger ones," said the minister.
He had led the crackdown on al Qaeda which waged a campaign of shootings and bombings against foreigners and Saudi security personnel between 2003 and 2007.