The Saudi authorities say they have arrested five more suspects in connection with last month's suicide bombings in the capital, Riyadh.
The Saudis have been trying to crack down on al-Qaeda
The Saudi interior minister, Prince Nayef Bin Abdul Aziz, told al-Riyadh newspaper that one of those detained might have played a "major role".
Thirty-four people, including nine bombers, died in the 12 May attacks on Western compounds in Riyadh.
The latest arrests bring to 30 the number of those detained on suspicion of involvement.
The US and Saudi authorities blame the al-Qaeda network for the bombings.
Prince Nayef said the new suspects were arrested during security checks in the past two days.
He said four belonged to the group that carried out the Riyadh attacks - although their roles were "unclear".
However, he added: "There's a fifth who was arrested before that who might have had a major role".
Prince Nayef did not identify or give any details about the latest suspects.
Most of the suicide bombers responsible for the attacks on the United States on 11 September 2001 were Saudi nationals, and Riyadh has been criticised for not doing enough to fight Islamic radicals.
However, since last month's bombing the Saudi authorities have been keen to publicise operations against suspected militants.