The Saudi authorities have arrested 18 suspected spies, including an Iranian and a Lebanese, on charges of espionage for a foreign country, the interior ministry said.

"Sixteen Saudis, an Iranian and a Lebanese were arrested in co-ordinated and simultaneous operations in four regions of the kingdom," including the capital Riyadh and Mecca, the ministry said in a statement on Tuesday.

Interior Ministry spokesman Mansour al-Turki told state television that the arrests were made four days ago and the suspects were being investigated before being handed over to judicial authorities.

'Case of espionage'

"This is a case of espionage and those have been involved with a spy network working for a foreign country," Turki told state television.

"They were gathering information about installations and vital areas in the country and providing intelligence agencies of that state with it," he added, without naming the state.

News of the arrests come as rights activists on Tuesday reported that Saudi security forces had arrested several Shias across the kingdom, including two clerics, over the past days for unspecified reasons.

Since early 2011, mainly Shia towns in the eastern province have seen sporadic protests and confrontations between police and Shia residents who complain of marginalisation.

There are an estimated two million Shias in the Sunni-dominated kingdom of about 27.5 million people,

Source: Agencies