Saudi Arabia has arrested 208 people it says were plotting assassinations and an attack on a logistical oil facility, in one of the biggest such operations in the kingdom.
General Mansur al-Turki, an interior ministry spokesman, said on Wednesday that the suspects were comprised of six cells.
He said: "One of the cells was plotting to attack an auxiliary oil facility in the Eastern Province, a logistical facility, not an oil refinery."
Al-Turki did not give details about the targeted site, but said the men had been arrested over the past few months in various parts of the country.
Al-Turki said another cell was plotting to smuggle rockets into the kingdom, which has been battling suspected al-Qaeda fighters since they launched a spate of bombings and shootings in May 2003.
An interior ministry statement, carried by official Saudi media, said security forces had thwarted an "imminent" attack on the auxiliary oil facility by rounding up the eight members of the cell, which it said was led by a foreign resident.
Hussein Shobokshi, a Saudi journalist speaking from Jeddah, told Al Jazeera: "This is consistent with what has been planned in the past ... applied by al-Qaeda and the like."
Saudi Arabia, the world's biggest oil producer and exporter, announced in February 2006 that it had foiled an attempt to blow up an oil processing plant, the world's largest, in Abqaiq in the Eastern Province.
The statement said the suspects were rounded up in a series of "pre-emptive" operations against members of the "deviant" group, official terminology for al-Qaeda suspects.
Some of those detained had formed "an assassination squad to target (Islamic) scholars and security men," it said.
Another cell headed by an "infiltrator" who is an "expert in launching rockets" was plotting to smuggle eight rockets across the border to use them in "terrorist operations" inside the country, the ministry said.
More than half of those arrested, 112, were linked to "external" parties.
Such parties recruited fighters and sent them to troubled regions in order to take part in fighting in these countries and then return to "spread sedition and chaos" in Saudi Arabia, the ministry said.
It was apparently referring to Iraq, where Saudis are among foreign fighters fighting US-led forces.