Saudi Arabia said on Tuesday it had uncovered an al Qaeda militant group with links to "extremist elements" in Syria and Yemen that had been plotting to assassinate officials and attack government and foreign targets.
The cell comprised 62 members, including 59 Saudi militants, a Yemeni, a Pakistani and a Palestinian, Interior Ministry spokesman Major General Mansour al-Turki said.
Speaking in a live televised briefing, Turki said the cell had links to the ultra-hardline Islamic State of Iraq and the Levant (ISIL), which is both a powerful Islamist force in Syria's war and an anti-government combatant across the border in turbulent Iraq.
He said some members of the cell were still at large.
"They ... started constructing components of the organisation, means of support and planning for terrorist operations targeting government installations, foreign interests and assassinating security personalities," he said.
The conservative Islamic kingdom, the world's largest oil exporter, has grown increasingly concerned about radicalisation this year because the war in Syria has spurred what they see as a surge in online militancy.
Officials are worried about a new al Qaeda armed campaign: Saudi Arabia faced an al Qaeda insurgency from 2003 to 2006 in which militants targeted residential compounds for foreigners and Saudi government facilities, killing dozens of people.
The kingdom responded by arresting thousands of suspected militants and launching a media campaign to discredit their ideology with the backing of influential clerics and tribal leaders. The courts have sentenced thousands of Saudi citizens to prison terms for similar offences over the past decade.
Turki said an investigation into social media postings "led security forces after months of hard work to pinpoint suspicious activities that unveiled a terrorist organisation through which the elements of al Qaeda in Yemen were communicating with their counterpart elements in Syria in coordination with a number of misguided (people) at home in various provinces of the kingdom."
Authorities had found a laboratory to make explosives and seized funds intended for the militant cell close to one million Saudi riyals ($266,600).
Some of those in the cell had previously gone through rehabilitation, Turki said, referring to educational courses for detained Islamist militants intended to wean them off violence.
Turki said security forces were monitoring "suspicious actions on social networking" "especially after becoming a spacious arena for all extremist groups".