When asked Sunday whether the four men in custody belonged to al Qaeda, Saudi Interior Minister Prince Nayef said, "All indications point to that."
This week's terror attacks in Saudi Arabia and Morocco are stark reminders that al Qaeda and its world-wide terror network may be damaged, but it hasn't been defeated, reports CBS News Correspondent Randall Pinkston.
U.S. counterterrorism officials say they expect additional al Qaeda bombings at lightly defended targets in Asia and Africa. There is also evidence senior al Qaeda operatives have found safe haven in Iran, where they planned and directed this week's strike on Saudi Arabia, as well as future attacks, the officials say.
The Saudi interior minister says three of the nine attackers believed to have carried out the May 12 Riyadh bombings were wanted in connection with an earlier investigation of a weapons cache. The Saudi government linked the weapons to 19 suspects believed to be receiving orders directly from the Saudi-born bin Laden. The suspects planned to use the weapons to attack the Saudi royal family and American and British interests, the government says.
For a year and a half, U.S. and allied forces have chased al Qaeda from its base of operation in Afghanistan to outposts around the world.
Osama bin Laden and his top leaders are on the run, but the terrorists they trained are still able to operate, even without a base or central command structure.
Jessica Stern, a terrorism expert at the Kennedy School Of Government, tells CBS News, "What I find very troubling is it's proving itself very adaptable, very cable of evolving to meet new circumstances so that we see more groups coming into the alliance."
One of the new members of the al Qaeda alliance, according to U.S. intelligence officials, is the radical group, Hezbollah.
While most recent intelligence has pointed toward attacks in Southeast Asia, the Arabian peninsula and East Africa, officials said similar strikes in Europe and the United States are also a possibility.
During the past several months, authorities have detained several people they suspect are advance scouts sent by al Qaeda to conduct surveillance inside the United States, U.S. officials say. Their activities are still being investigated.
"The enemies of freedom are not idle, and neither are we," President Bush said in his weekly radio address on Saturday. "Our government is taking unprecedented measures to defend the homeland. And from Pakistan to the Philippines, to the Horn of Africa, we are hunting down al Qaeda killers."
But al Qaeda and its allies are hunting down U.S. interests at the same time, by seeking out softer targets. Since September 11th, al Qaeda has been tied to at least eight attacks: