Islamabad, Pakistan (CNN) -- Pakistani authorities have arrested Younis Al Mauritania, whom they called a senior al Qaeda leader, and two other al Qaeda figures in the suburbs of Quetta, the military announced Monday.

Osama bin Laden personally tasked Al Mauritania "to focus on hitting targets of economic importance in United States of America, Europe and Australia," with U.S. targets including gas and oil pipelines, dams and oil tankers, the Pakistani military said in a statement.

"This is one of al Qaeda's key operatives, and getting him off the streets has been a top priority," said a U.S. senior counterterrorism official.

The official could not immediately confirm the arrest, but said Al Mauritania has "been active in planning attacks, and threats associated with him were partially responsible for the Europe travel alert that was issued last year. His capture would deal a major blow to the terrorist group's activities, and would be another in a string of recent wins against al Qaeda."

U.S. intelligence agencies provided "technical assistance" in planning and conducting the operation, the Pakistani military statement said. Pakistan's Inter Services Intelligence has a "strong, historic intelligence relationship" with the U.S. agencies, it added, and the two nations continue to cooperate to enhance security.

That cooperation has resulted in the prevention of a "number of high-profile terrorist acts," not only in Pakistan and the United States but elsewhere in the world, the military statement said.

The terror organization that claimed credit for the September 11, 2001 attacks among others has suffered a series of blows this year.

In May, its longtime leader bin Laden was killed in a clandestine U.S. raid on his compound in Pakistan. His deputy, Ayman al-Zawahiri, became al Qaeda's leader.

In late August, officials said Zawahiri's second-in-command, Atiya Abdul Rahman, was killed in Pakistan. Rahman died in an apparent drone strike. A U.S. official said Rahman was in charge of running daily operations for the group. He previously was bin Laden's operations chief.

And U.S. officials have said they believe that Ilyas Kashmiri, a senior figure in al Qaeda described as the organization's "military brain," was killed in June in a drone attack in Pakistan. Kashmiri operated his own terrorist group, Harakat-ul-Jihad-Islami, or Movement for an Islamic Holy War.

Defense Secretary Leon Panetta said in July that the United States "is within reach of strategically defeating al Qaeda."

"I think we have them on the run. I think now is the moment, now is the moment following what happened with bin Laden to put maximum pressure on them because I do believe that if we continue this effect that we really can cripple al Qaeda as a threat to this country," Panetta said.