A Pakistani policeman stands alert in a bunker in Quetta after the Pakistani army annouced that a senior Al-Qaeda leader believed to have been responsible for planning several attacks has been arrested. (BANARAS KHAN/AFP/GETTY IMAGES)

The Pakistani military said Monday that its top spy agency had worked with the CIA to arrest three senior al-Qaeda figures near the southwestern city of Quetta, including one militant leader who was directed by Osama bin Laden to strike economically significant targets in the West.

It was unclear how high that militant, whom the army identified as Younis al-Mauritani, ranked in the al-Qaeda hierarchy, or when the arrests took place. But the unusual announcement, backed up by the White House, appeared to signal renewed cooperation between the top Pakistani and U.S. intelligence agencies, whose long-fraught relations decayed to a near breaking point this year.

The Pakistani military said al-Mauritani was plotting strikes on American dams and gas and oil pipelines and planning bombings of U.S. ships and oil tankers using explosives-rigged speed boats. Pakistan’s Inter-Services Intelligence agency detained him along with two other senior leaders, Abdul Ghaffar al-Shami and Messara al-Shami, in an operation planned and carried out with the help of “technical assistance” from U.S. intelligence, the military said in a statement said.

In Washington, Tommy Vietor, a White House spokesman, said the action had “led to the capture of a senior al-Qa’ida operative who was involved in planning attacks against the interests of the United States and many other countries.”

Both the White House and the Pakistani military portrayed the arrests as a significant blow to al-Qaeda, an organization that American officials have said may be near strategic defeat following the U.S. commando raid that killed Osama bin Laden at his hideout in Pakistan in May.

The announcement of the arrests came one week after U.S. and Pakistani officials said al-Qaeda’s second-in-command, Atiyah Abd al-Rahman, had been killed in a CIA drone strike in the Waziristan area of Pakistan’s rugged tribal region. The officials characterized his death as a major loss for al-Qaeda.

According to the Long War Journal, a U.S.-based Web site that covers the war on terror, a detained German-Afghan al-Qaeda figure falsely identified al-Mauritani last year as the organization’s No. 3 operative. Senior U.S. intelligence officials countered at the time that while al-Mauritani was a senior member of al-Qaeda’s committee to plan attacks on the West, he was not its leader, the Web site reported.

Pakistan’s top spy agency, known as the ISI, has long worked closely with the CIA on counterterror operations and hunts for senior al-Qaeda figures, many of whom are believed to be based in the Pakistani mountains bordering Afghanistan. But relations between the agencies have frayed in recent years over disagreements on CIA drone strikes, which Pakistani officials say have become too frequent and unilateral, and over U.S. beliefs that Pakistani spies provide support to some Islamist militants they deem strategically useful allies.

Cooperation took a nose dive in January after a CIA security contractor, Raymond Davis, fatally shot two Pakistanis he sad were trying to rob him in the eastern city of Lahore. Relations deteriorated further after the bin Laden raid, which the United States carried out without alerting Pakistani officials, in part out of fear that they would scuttle the plan. Pakistani officials said joint operations had been cut off.

The Pakistani statement Monday, however, praised the countries’ intelligence relationship as “strong” and its cooperation as “intimate.”

“Both Pakistan and the United States Intelligence agencies continue to work closely together to enhance security of their respective nations,” the statement said.