Sixteen suspected militants arrested in Saudi Arabia are linked to Osama Bin Laden's al-Qaeda network, the interior minister has said.
Triple suicide attacks in May targeted Westerners
Those detained in a series of raids across the country on Monday have been accused of planning attacks on key installations.
When asked by the London-based Arabic newspaper Al-Sharq al-Awsat if the suspects had any links to al-Qaeda, Interior Minister Prince Nayef replied: "Certainly yes."
He urged Saudis to be vigilant when donating
money to charity because of fears al-Qaeda was using such organisations to finance its attacks.
Monday's arrests were made during raids on a small farm and rest house in the capital Riyadh as well as hideouts in the central province of Qassim and in the east of the country.
Security forces seized rocket-propelled grenades, explosives and detonators, as well as night vision binoculars, monitoring cameras, computers, fake passports and ID cards.
Prince Nayef said reports that the weapons had come from Yemen or Iraq were being investigated.
"We do not like to speculate before we are certain of the matter 100%," he said. "We have to know how did they reach these persons and how and who helped do this and from where."
'Beware' collection boxes
Saudi Arabia launched a determined crackdown on suspected militants following May's triple suicide attacks on Western compounds in Riyadh.
Al-Qaeda has been blamed for the attacks, which killed 35 people including nine bombers.
Dozens of people have been arrested. Number two on the wanted list, Ali Abdul Rahman al-Ghamdi, gave himself up in June.
Prince Nayef told Al-Sharq al-Awsat newspaper: "The time has not yet come to confirm the end of the search for the terrorist cells or disclose all the facts we have. We still have time before we reach this stage."
He warned people to be wary about putting money in collection boxes at the entrance to some mosques in Saudi Arabia.
"Those wishing to contribute must verify the parties to which this money will go," he said.
He urged Saudi citizens "not to contribute unknowingly to the killing of people by paying money to suspicious boxes or parties".