Washington ? Leaders of the congressional intelligence committees said Sunday the capture of a top al-Qaida operative was a major blow to the terror group and will give U.S. officials the chance to learn about attacks that may have been planned.

Khalid Shaikh Mohammed, suspected mastermind of the Sept. 11 attacks, is “really a big fish,” said Sen. Pat Roberts, chairman of the Senate committee. “If there was one person that we wanted to get, it was this man.”

Roberts, R-Kan., portrayed Mohammed’s arrest Saturday in Pakistan as “a giant step backward for the al-Qaida. This must send a message — will send a message to the al-Qaida, who is mounting a spring offensive for use in Afghanistan. Now their operations commander is simply out of operations.”

The House chairman, Rep. Porter Goss, predicted that Mohammed’s capture “is going to lead to other successful activities very shortly, I’m sure.”

“This is a success on the war on terror and the organization of it, the unraveling of it. This is what we’ve promised to do — to win the war on terror,” Goss, R-Fla., told ABC’s “This Week.”

U.S. authorities have taken Mohammed out of Pakistan to an undisclosed location after capturing him in a joint raid by CIA and Pakistani agents, a senior government official in Pakistan said Sunday.

Mohammed, 37, is perhaps the most senior al-Qaida member after bin Laden and his deputy, Ayman al-Zawahri.

“We got the operations manager; more coming. Look out, al-Qaida,” Roberts told “Fox News Sunday.”

A naturalized Pakistani who was born in Kuwait, Mohammed is on the FBI’s most-wanted list and allegedly had a hand in many of al-Qaida’s most notorious attacks. The U.S. government had offered a reward of up to $25 million for information leading to his capture.

Roberts and Goss said that Mohammed could provide invaluable information to U.S. investigators if he talks.

“We can learn from him, I hope,” about what operations “are out there that we can defend against and forestall,” Goss said.

“This gives us obviously more focus and more clarity on exactly where to go and what to look at.”