Attorney General John Ashcroft warned Sunday that religious or political groups normally free from government intrusion could be monitored by agents if they are suspected of engaging in terrorism.

"People who hijack a religion and make out of it an implement of war will not be free from our interest," he declared as officials took to the Sunday news shows to debate America's new anti-terrorism police powers.

The Senate's top Democrat said he might support the narrow use of one of the most controversial tactics — secret military tribunals to try terrorists.

"Under certain circumstances, very, very restricted circumstances, depending on how it's handled, I'm willing to look at it," Senate Majority Leader Tom Daschle of South Dakota said.

"With regard to the situation in Afghanistan in particular, trying a Taliban or terrorist or ... people involved in terrorist activity, clearly there's at least the possibility that something like that might have merit," Daschle said on NBC's Meet the Press.

The debate offered a preview of a Senate hearing this week at which Ashcroft will address criticisms of both liberal Democrats and conservative Republicans concerned the new tactics will erode civil liberties.

Meanwhile, law enforcement officials told The Associated Press that investigators have gathered evidence showing similarities among the last three terrorist attacks against Americans by Usama bin Laden's supporters.

Those attacks include the Sept. 11 suicide hijackings, the October 2000 bombing of the USS Cole in Yemen and the 1998 bombings of two U.S. embassies in Africa.

The officials, who spoke only on condition of anonymity, said the similarities included the way the attacks were planned, communicated and carried out, and the way the attackers were trained. The officials declined to be more specific.

"There are certainly similarities among the three, some of which have emerged more clearly in the last few weeks," one official said.

The investigators said they also are examining whether some of the same people were involved in planning and assisting the three attacks. One official said authorities are waiting for more information from authorities in Yemen and other countries about certain suspects.

On the news shows, Ashcroft previewed his appearance Thursday before the Senate Judiciary Committee, where he will confront criticism about some of his department's hardest line tactics.

"We're going to do what we need to do to protect the American people," Ashcroft said on ABC's This Week when asked whether restrictions designed in the 1970s to protect religious and political groups from government monitoring were being eased.

"If a religion is hijacked and used as a cover for killing thousands of Americans, we're interested in that," he said.

He added, "We will respect the rights of political freedom and religious freedom, and we are deeply committed to that. But for so-called terrorists to gather over themselves some robe of clericism ... and claim immunity from being observed, people who hijack a religion and make out of it an implement of war will not be free from our interest."

Ashcroft told Fox News Sunday that military tribunals would be limited to non-U.S. citizens and "not just normal criminal activity, but war crimes." He refused to rule out military tribunals for any foreigners detained on U.S. soil.

"Can you imagine apprehending a terrorist, either in the deserts of Afghanistan or on the way to the United States to commit a crime, and having to take them through the traditional justice system?" Ashcroft asked.

"Reading them the Miranda Rights? Hiring a flamboyant lawyer at public expense? Having sort of Usama television ... allowing that kind of propaganda to go out, jeopardizing American assets in the intelligence community and in the war? Putting a courthouse and a community as a target for terrorism?"

Rep. Bob Barr, R-Ga., a conservative former federal prosecutor, said he opposed tribunals for any suspect detained on U.S. soil. "I'm not worried about tribunals, for example, overseas, but domestically we have to abide by the Bill of Rights," he told ABC.

Sen. Joseph Lieberman, D-Conn., the former vice presidential candidate, said he supported using tribunals for terrorists who engaged in acts of war but opposed them if used against people legally in the United States.

In other developments:

—Ashcroft said there continues to be no evidence the deadly anthrax mailed in four recent letters was the work of foreign terrorists or a foreign government. Investigators believe a single person who lived in the United States was behind all four attacks. Agents have delayed opening the most recent letter to Sen. Patrick Leahy, D-Vt., until scientists are fully ready to analyze it.

—Several hundred National Guard members have been asked to assist inspections at U.S.-Canadian crossings. Ashcroft said he also wants military helicopters to patrol the 4,000-mile border. He said the moves were "not militarizing our border with Canada" but rather designed to fill gaps created when agents who traditionally patrol the border were shifted to inspecting cars, trucks and cargo after Sept. 11.