FBI Director Robert Mueller told a Senate committee February 11 that the United States and its allies have inflicted a series of significant defeats on al-Qaeda and its global terrorist network, here and abroad, "but the terrorist enemy ... is far from defeated."

"The enemies we face are resourceful, merciless and fanatically committed to inflicting massive damage on our homeland, which they regard as a bastion of evil," Mueller said during a Senate Select Intelligence Committee hearing. "In this war, there can be no compromise or negotiated settlement."

Mueller testified that terrorists could strike by poisoning food and water supplies with cyanide, botulism or ricin. They also could strike at critical computer systems, which support the nation's infrastructure, or assault U.S. railroads, aircraft, oil and natural gas facilities, or electric power grids, he said.

"The al-Qaeda network will remain for the foreseeable future the most immediate and serious threat facing this country," he said.

He said that FBI investigations have revealed there is a widespread militant Islamic presence in the United States, and that several hundred of these extremists are linked to al-Qaeda.

"The focus of their activities centers primarily on fundraising, recruitment, and training," Mueller said. "Their support structure, however, is sufficiently well-developed that one or more groups could be ramped up by al-Qaeda to carry out operations in the U.S. homeland."

The FBI is also monitoring potential threats from Islamic extremist groups such as Hizballah and HAMAS, he said, which have been attempting to raise funds through other groups in the United States.

Mueller said the FBI has charged 197 suspected terrorists with crimes, 99 of whom have been convicted to date. And, the FBI has helped with the deportation of 478 individuals with suspected links to terrorist groups, he said.

The Senate Select Intelligence Committee was conducting its annual hearings on the U.S. intelligence community and national security threats in both open and closed sessions. In addition to hearing testimony from Mueller, the committee heard from CIA Director George Tenet and Vice Admiral Lowell Jacoby, director of the Defense Intelligence Agency. It was also expected to hear testimony from Carl Ford, assistant secretary of state for intelligence and research.