Authorities would not say when the men were arrested or give further details about the operation to track them down, except to say it was carried out by Pakistan's Inter-Services Intelligence agency (ISI) and members of the Frontier Corps paramilitary force.
The United States provided information that led to the operation, said a senior Pakistani intelligence official, though he would not specify what that information was.
"All I know is that some technical assistance was provided by the Americans," the official said, speaking on the condition of anonymity. "Leads were provided which led to this operation, which was conducted independently by us."
The intelligence official had no information on what Mauritani had been planning. A prepared statement issued by Pakistan's military said the al-Qaeda commander had been plotting attacks on a variety of U.S. economic interests, including gas and oil pipelines and hydroelectric dams.
Mauritani also had been planning to target American ships and oil tankers with speedboats filled with explosives, according to the statement.
Pakistani military authorities said al-Qaeda leader Osama bin Laden had asked Mauritani to focus on targets of economic importance to the United States, Europe, and Australia. A team of U.S. Navy SEALs killed bin Laden in a raid May 2 on his compound in the Pakistani city of Abbottabad, just north of the capital, Islamabad.
Pakistani officials said that while they were not aware of Mauritani's exact position in al-Qaeda's hierarchy, he headed the terror network's international operations. The officials called his capture crucial.
"He played an absolutely central role in planning and coordinating al-Qaeda's operations in Europe, plots that targeted both European and American interests," said a U.S. official who requested anonymity.
His arrest comes nine days after U.S. officials reported that al-Qaeda's second-in-command, Atiyah Abdul Rahman, was killed in an American drone missile strike in Pakistan's Waziristan tribal region. U.S. officials called Rahman's death a major blow to al-Qaeda, particularly on the heels of bin Laden's killing.
Pakistani military and civilian leaders were deeply angered by President Obama's decision to carry out the bin Laden operation without consulting Islamabad. In announcing Mauritani's arrest, the Pakistani military's statement stressed the collaboration between the CIA and the ISI.