Senators defended on Sunday a purported CIA airstrike that Pakistani officials said killed at least 17 people in a village near the border with Afghanistan but not the intended target, Al Qaeda's No. 2 leader.

"We apologize, but I can't tell you that we wouldn't do the same thing again" in going after Ayman al-Zawahiri, said Sen. John McCain, R-Ariz.

McCain said it is a "cautionary tale" about the fate of the terrorist network's leaders that the U.S. "didn't take them out" long ago. He said the United States must hunt them down wherever they are hiding.

"We have to do what we think is necessary to take out Al Qaeda, particularly the top operatives. This guy has been more visible than Usama bin Laden lately," McCain said on CBS' "Face the Nation."

A U.S. counterterrorism official, who spoke on condition of anonymity because of the information's sensitivity, said it's still unclear if al-Zawahiri was killed in the attack.

Pakistani officials have strongly condemned the strike. The White House declined to comment on the attacks on Sunday, except to praise President Gen. Pervez Musharraf as well as Pakistan as "a valued ally on the war on terror." Officials at several U.S. agencies have not immediately provided details about the attack.

The FBI anticipates performing DNA tests on the victims, a law enforcement official said Saturday.

Islamic groups staged demonstrations across Pakistan on Sunday to denounce the attack. A protest in Karachi drew 10,000 people, and chants of "Death to America" were heard.

Sen. Evan Bayh, D-Ind., said the real problem is that the U.S.-allied Pakistani government does not control the region along the mountainous border with Afghanistan, where the attack occurred. Many Al Qaeda and Taliban combatants are believed to have taken refuge there.

"It's a regrettable situation, but what else are we supposed to do?" Bayh said in a televised interview." "It's like the wild, wild west out there. The Pakistani border is a real problem."

Pakistani intelligence officials have told The Associated Press that al-Zawahiri was invited to a dinner marking an Islamic holiday in the border village of Damadola, but that he did not show up.

Sen. Trent Lott, R-Miss., said strikes are necessary to get at Al Qaeda leaders in Pakistan who are directing anti-American violence in Iraq. "My information is that this strike was clearly justified by the intelligence," Lott said.

Both Bayh and Lott serve on the Senate Intelligence Committee.

Bayh said the CIA had been watching the area for several days and that the agency would not have conducted such an operation without extraordinarily high levels of intelligence. Bayh said he has "every reason to believe" that high-ranking officials in the Pakistani government were told in advance of the strike.