The FBI warning also warned that al-Quaida could launch new attacks in the United States or against American interests overseas.
The orange alert is the fourth-highest stage on the five-level U.S. terror alert color scale and is set by a group of Bush administration officials from the intelligence and homeland security agencies, among others.
Homeland Security Secretary Tom Ridge encouraged governors and mayors to utilize additional police “and particularly discussed with them the venues in which there will be large public gatherings,” said Asa Hutchinson, undersecretary for homeland security.
In a statement, Ridge said that the decision to raise the national threat level hinged on information from U.S. intelligence agencies that al-Qaida has entered an “operational period” worldwide that may include attacks in the U.S. as evidenced by recent bombings in Saudi Arabia and Morocco.
“While there is not credible, specific information with respect to targets or method of attack, the use of tactics similar to those seen in recent terrorist attacks overseas include small arm equipped assault teams, large vehicle borne explosive devices, and suicide bombers,” Ridge said in the statement.
“These attacks underscore terrorists’ desires to attack soft targets. Weapons of mass destruction, including those containing chemical, biological or radiological agents or materials, cannot be discounted,” he added.
Ridge was reportedly called out of a congressional hearing Tuesday to attend an emergency meeting at the White House to discuss concerns that intercepted communications indicate the possibility of an anti-American attack.
The move comes as diplomats said new attacks in Saudi Arabia appeared “imminent” and moved to close U.S. and British embassies and consulates in the kingdom through the weekend.
Last week’s nearly simultaneous bombings of residential compounds housing Western workers in Riyadh showed that al-Qaida “remains active and highly capable,” said the FBI bulletin that was sent to local and state law enforcement agencies.
According to media reports, the bulletin was first issued Friday with another version disseminated Tuesday that included the FBI’s concern that “Saudi Arabia and Morocco attacks [are] a possible prelude to U.S. attacks.”
The U.S. intelligence community “assesses that attacks against U.S. and Western targets overseas are likely; attacks in the United States cannot be ruled out,” the FBI communication said, according to an Associated Press report on the bulletin, which was provided by anonymous federal law enforcement officials.
“Further, these attacks suggest that al-Qaida may be deterred by enhancing security and changes in the security countermeasures adopted by potential targets,” the bulletin reportedly said.
White House spokesman Ari Fleischer, asked about the warning Tuesday, said “chatter” picked up by U.S. agencies suggested new attacks were possible.
“We’ve seen this before and we want to do everything we can to be vigilant,” Fleischer said on NBC’s Today show.
The FBI bulletin came out as more than 60 bureau agents continued their work with Saudi law enforcement to investigate the Riyadh bombings. Four men believed to be part of an al-Qaida cell in Saudi Arabia have been arrested in connection with the attacks, Saudi officials announced Monday.
Prince Bandar bin Sultan, Saudi Ambassador to the U.S., told reporters in Riyadh that “there is chatter, a high level of chatter regionally and in other international spots” about possible attacks in Saudi Arabia or the U.S.
“My gut feeling tells me something big is going to happen here [in Saudi Arabia] or in America,” Bandar said.
With security threats on the rise, the U.S. and British embassies in Riyadh were the first to announce Tuesday they would be closed Wednesday. The American embassy’s Web site said officials had received credible information that further attacks are being planned against unspecified targets in Saudi Arabia.
Later Tuesday, Germany also said its embassy in Riyadh as well as a satellite office in Jeddah would be closed to the public at least until Friday.
U.S. consulates in Jeddah and Dhahran will also be closed on Wednesday due to the threat of a new attack. The American and British facilities will stay shuttered through at least the weekend.