WASHINGTON, March 21 (IslamOnline & News Agencies) - CIA director George Tenet said Tuesday, March 19, that despite U.S. successes in the war on terrorism, U.S. diplomatic and military installations overseas remain at high risk of attack by Al-Qaeda fighters, news agencies reported.

Osama bin Laden and his Al-Qaeda network are still "the most immediate and serious threat" that the United States faces, Tenet claimed in testimony before the Senate Armed Services Committee six months after the September 11 terrorist attacks on the United States, Agence France-Presse (AFP) reported.

He claimed that the United States has made "enormous progress" against Al-Qaeda in Afghanistan and had disrupted its global operations with the arrests of 1,300 people in 70 countries.

However, he added, "We assess that Al-Qaeda and other terrorist groups will continue to plan to attack this country and its interests abroad."

Terrorists have considered attacks in the United States against high profile government and private facilities, famous landmarks and key infrastructure such as bridges, harbors, airports, dams and financial centers, he said.

He singled out countries such as East Africa, Israel, Saudi Arabia, Turkey, Pakistan and Afghanistan, as being the most likely places that the attacks could take place.

"Operations could be launched by Al-Qaeda cells already in place in major European cities and the Middle East," he alleged.

Tenet's warning followed the State Department's release Sunday, March 17, of a "worldwide caution" to American citizens around the globe to be on alert for possible attacks against U.S. interests and individuals, saying that the government "continues to receive credible reports that extremist individuals are planning additional terrorist actions against U.S. interests."

"Such actions may be imminent and include suicide operations," the warning said. "We remind American citizens to remain vigilant with regard to their personal security and to exercise caution."

Tenet, in laying out the U.S. intelligence community's assessment of the threats facing the United States around the world, said that a top U.S. concern was Al-Qaeda's stated readiness to launch unconventional attacks.

"Terrorist groups worldwide have ready access to information on chemical, biological and even nuclear weapons through open sources," he said.

"Documents recovered from Al-Qaeda facilities in Afghanistan show that bin Laden was pursuing a sophisticated biological weapons research program," Tenet alleged.

"We also believe that bin Laden was seeking to acquire or develop a nuclear device. Al-Qaeda may be pursuing a radioactive dispersal device, what some call a dirty bomb," he claimed.

Tenet warned that Al-Qaeda or other groups also might try to cause widespread toxic or radiological contamination by launching a conventional attack on chemical or nuclear facilities in the United States.

Tenet also predicted that cyber attacks on critical infrastructure would become "an increasingly viable option" for terrorists.

Despite his warnings, Tenet also claimed that the U.S.-led "war on terrorism", however, has dealt "severe blows to Al-Qaeda and its leadership." He said that the group is no longer able to train and recruit in Afghanistan, and the United States and its allies are uncovering plans and breaking up cells around the world.

"These efforts have yielded the arrest of over 1,300 extremists believed to be associated with Al-Qaeda operatives in over 70 countries," he said.

"That said, I must repeat that Al-Qaeda has not been destroyed," Tenet stressed.

Testifying alongside Tenet at the hearing was Vice Adm. Thomas R. Wilson, director of the Defense Intelligence Agency, who emphasized the danger of increased and prolonged insurgency warfare in Afghanistan, according to a report Wednesday in The Washington Post.

Wilson warned of "a very widespread probability of insurgency-type warfare" in both rural and urban areas in Afghanistan, the article said, adding that the U.S. military had to prepare for the possibility that Al-Qaeda and Taliban operations "may bridge the difference between terrorism and… insurgent warfare."