RIYADH, (Agencies) – Saudi Arabia said on Wednesday announced it had arrested 208 people for involvement in several cells that planned an “imminent attack” on an oil installation, and attacks on clerics and security forces.

According to the Saudi Press Agency, one of the cells was planning to smuggle in missiles, while a cell of eight militants led by a foreign resident planned an attack on an oil facility in the Eastern Province said the report, citing an Interior Ministry statement.

“Security forces foiled an imminent attack on an oil support installation in the Eastern Province after the perpetrators prepared themselves and set a date,” reported the Saudi Press Agency.

The report said 18 of those arrested belonged to a cell led by an “expert in launching missiles” who had slipped into the country. Another 22 were part of a group that plotted to kill clerics and security forces, it said.

It also said the arrests included a “media cell” of 16 in Medina which aimed to promote “takfiri” ideology; the ideas held by radicals that support violence against Muslims branded as infidels and apostates.

The government has warned clerics in recent months to do more to stop Saudi nationals from heading to Iraq to join al Qaeda militants fighting U.S. forces and the U.S.-backed Shiite Muslim government.