A top Bush administration official says the recent arrest of a suspected terrorist in Pakistan could destabilize the al-Qaida terrorist network.

Attorney General John Ashcroft told members of the Senate Judiciary Committee that the arrest of key al-Qaida member Khalid Shaikh Mohammed could have profound implications for the war on terrorism.

"The capture of Khalid Shaikh Mohammed by Pakistani authorities, in coordination with the CIA, is a severe blow to al-Qaida that could destabilize their terrorist network worldwide," he said.

Attorney General Ashcroft described Khalid Shaikh Mohammed as the "operational mastermind" of the September 11 terrorist attacks. He says the Mohammed arrest is an opportunity for U.S. intelligence officials to prevent future attacks.

Mr. Ashcroft says CIA and FBI agents are moving rapidly to exploit the opportunity by reviewing materials found in the apartment where the arrest took place.

Mr. Ashcroft also announced the recent arrest of two men from Yemen who have been charged with providing money and weapons to al-Qaida. U.S. officials are seeking their extradition from Germany where they are currently being held. One of the men is alleged to have personally handed Osama bin Laden $20 million from a terrorist fund-raising network.

FBI Director Robert Mueller told the Senate committee that U.S. counter-terrorism efforts have helped to thwart more than 100 terrorist attacks since September 11.

Attorney General Ashcroft says terrorists around the world are "getting the message".

"We are arresting and detaining potential terrorist threats," he said. "We are dismantling the terrorist financial network and we are disrupting potential terrorist travel and we are building our long term counter-terrorism capacity. We are winning the war on terrorism."

Senate Democrats were generally supportive of the counter-terrorism efforts. But the top Democrat on the Judiciary Committee, Senator Patrick Leahy of Vermont, urged the Bush administration to be more forthcoming about its plans for new laws that would expand the power of law enforcement agencies to crack down on suspected terrorists.