ISLAMABAD, Pakistan  — Working with the CIA, Pakistani spies arrested three members of al-Qaida, including a top operative alleged to have been tasked by Osama bin Laden with targeting American economic interests around the world, Pakistan’s army said Monday.

The arrest of Younis al-Mauritani close to the Afghan border is another blow to al-Qaida, which is still reeling following the deaths of bin Laden on May 2 in an American raid and the organization’s second-in-command, Atiyah Abd al-Rahman, in a CIA missile strike last month.

It is also a sign that ties between the CIA and Pakistan’s Inter-Services Intelligence agency are improving after a torrid few months due to tensions sparked by the operation that killed bin Laden and U.S. suspicions that the agency — which has historic ties to militants — was playing a “double game.”

The statement said the arrests took place in the southwestern city of Quetta, a large city long known for its militant connections, but did not say when. The fact that all three men were captured alive means they could give valuable information to interrogators.

“This operation was planned and conducted with technical assistance of United State Intelligence Agencies with whom Inter-Services Intelligence has a strong, historic intelligence relationship. Both Pakistan and United States Intelligence agencies continue to work closely together to enhance security of their respective nations,” the statement said.

The statement said al-Mauritani was mainly responsible for al-Qaida’s international operations and was tasked by bin Laden with focusing on hitting targets of economic importance in America, Europe and Australia. It said he was planning to target U.S. economic interests including gas and oil pipelines, power generating dams and oil tankers by using explosive-laden speed boats in international waters.

It named the other two detainees as Abdul-Ghaffar al-Shami and Messara al-Shami.

U.S. officials were not immediately available for comment.

Since the Sept. 11, 2001, attacks, Pakistan’s spy agency has cooperated with the CIA to arrest scores of al-Qaida suspects, most of whom were handed over to the United States. But there have been fewer high-profile arrests in recent years.

Many top al-Qaida commanders are still believed to live in Pakistan, and getting Islamabad’s cooperation in cracking down on the network has been a top American goal since 2001. But there have been persistent suspicions that the country was protecting militants. The fact that bin Laden was killed in an army town close to the capital, Islamabad, led to fresh doubts over Pakistan’s commitment.

U.S. officials have recently claimed al-Qaida’s capabilities have been seriously weakened due to drone strikes and arrests in recent years.