Terrorists have already planned future attacks against the United States, said CIA Director George Tenet Wednesday.

Tenet told a Senate intelligence committee in Washington that the CIA has undermined many plots, but several threats still remain.

“We assess that al-Qaeda and other terrorist groups will continue to plan to attack this country,” Tenet said.

Tenet provided the Senate Select Committee with an overview of the possible threats, including political unrest in Somalia, Indonesia, Colombia and Iran and also a suspected nuclear and biological weapons stockpile in Iraq.

Thus far, Tenet said, almost 1,000 suspected al-Qaeda members have been arrested in more than 60 countries.

Across the river in Virginia, John Walker Lindh, the American arrested for conspiring with the Taliban and al-Qaeda, was denied bond Wednesday.

U.S. Magistrate W. Curtis Sewell turned Walker down, saying he was a flight risk.

Walker’s attorney Jim Brosnahan claimed his client is “loyal to the United States and to his family.” He also said Walker “never fought with al-Qaeda, never signed up for (the group) and never had anything to do with terrorism.”

The prosecution disagreed.

“John Walker Lindh is a committed terrorist,” the prosecution said. “He not only talked the talk, but he walked the walk, carrying hand grenades and firearms and referring to his al-Qaeda brothers.”

After the hearing, Brosnahan requested that Attorney General John Ashcroft not speak about about the case publicly.

“I’d think the American people probably want the attorney general to focus on those people who really did the harm to this nation … and not take it out on John,” he said. “In my view … they have brought up the cannon to shoot the mouse.”

A grand jury indicted Walker on 10 counts Tuesday, and his formal arraignment is set for Feb. 11.

In Afghanistan, U.S. officials said three arrests were made late Tuesday in connection with the kidnapping of reporter Daniel Pearl.

“We are very optimistic,” one official told CNN. “We think he’s still alive.”

The men were taken into custody near Kandahar and have been linked to the computer from which e-mails regarding the kidnapping were sent to The Wall Street Journal.

They have been identified simply as “Fahd, Adil and Salman.”

Pearl disappeared two weeks ago while on his way to interview a well-known Muslim fundamentalist.

— Compiled by Leah Newman

Contributing: CNN and MSNBC reports