Washington ? Al-Qaida terrorists appear to be regrouping as a lethal threat with or without Osama bin Laden, congressional leaders said Sunday.

Lawmakers cited recently publicized warnings from U.S. officials and a bin Laden spokesman to underscore the persistent danger from terrorists chased from their Afghan havens.

They appear to be more capable of attacking Americans than they were a month or two ago, said Sen. Bob Graham, D-Fla., chairman of the Senate Intelligence Committee. He said bin Laden might be in Pakistan’s western tribal lands.

Added Sen. Richard Shelby of Alabama, the committee’s top Republican, “They could hit us any day.”

The senators offered no evidence of an impending attack other than the uncorroborated warnings issued lately, including one that al-Qaida could use fuel tanker trucks against Jewish interests in America.

But with the approach of Independence Day, an attractive target day for terrorists, foreboding was heard throughout the Sunday talk show circuit.

“They would love the symbolism” of attacking on July Fourth, said House Majority Leader Dick Armey, R-Texas. “We must be doubly alert on that day.”

It was left to Afghan President Hamid Karzai to sound a note of confidence about the progress made against al-Qaida and the Taliban both.

“They are a defeated force,” he said on CNN’s “Late Edition.” “They are on the run.” Individuals might be plotting terrorism but basically, “they’re criminals in hiding.”

Officials have not established the authenticity of an audio interview made public on the weekend in which bin Laden associate Sulaiman Abu Ghaith says the al-Qaida leader and most other top figures in the network are alive, well and ready to attack again.

“Lot of bravado there,” said Democratic Sen. Barbara Boxer of California, noting bin Laden did not look well at all when last seen on video.

Karzai said dismissively of bin Laden, “his days are anyway numbered.”

But Graham, for one, put some stock in the claims. “It’s not surprising that there is a statement that bin Laden is still alive,” he said on “Fox News Sunday.” “That’s the best assessment of U.S. intelligence.”

Regardless of bin Laden’s fate, al-Qaida appears to be regenerating, he said, and even the Hamburg, Germany, cell believed central to the Sept. 11 attacks has been showing signs of life.

“What we have seen is a disturbing pattern of the reformulation of al-Qaida and their renewed willingness and capability to conduct terrorist attacks.”

Bush administration officials have pointed to numerous indications of al-Qaida activity but questioned whether the network still has the command structure or communications to plan something from the top.

They believe midlevel operatives are having to do their own hasty planning with whatever tools they can muster, and the result could be more frequent but less sophisticated attacks than before.

A White House official speaking on condition of anonymity said the administration viewed the Ghaith remarks as no surprise, but would not comment on whether bin Laden may be alive or on the likelihood of a new attack.

Lawmakers said al-Qaida does not need bin Laden in order to go on.

“This snake can crawl without its head and we need to be aware of that,” Armey said.

Senate Minority Leader Trent Lott, R-Miss., agreed.

“This guy is still a huge problem if he’s alive – if he’s dead the people who work for him are still causing problems,” Lott said. “These people and their tentacles are all over the world.”

Ghaith said in his remarks, released as an audio file on Islamic Web sites, that bin Laden is in good health, his No. 2 man also survived the Afghan war and al-Qaida remains capable of harming the United States.

“The few coming days and months will prove to the whole world, Allah willing, the truth of what we are saying,” he said.

“I say ‘Yes’ to what American officials are saying … that we are going to carry out attacks on America.”

The statement also claimed responsibility for an April fire at a Jewish synagogue in Tunisia that killed 19 people. U.S. officials believe al-Qaida was behind it.