U.S. officials pressed Saturday to find a link between a terrorist threat to New York and Washington and the new leader of al Qaeda, Ayman al-Zawahiri, working with Pakistanis who are interrogating the terror group’s recently captured operations chief.

U.S. intelligence officials are watching a detention facility in Pakistan where Yunis al-Mauritani is being interrogated by the counterterrorism division of Pakistan Inter-Services Intelligence, or ISI. Pakistan’s military announced Sept. 5 that the ISI had captured Mauritani in a suburb of Quetta. “Al Mauritani was tasked personally by Osama Bin Ladan to focus on hitting targets of economical importance in United States of America, Europe and Australia,” the Pakistani military’s press release said. “He was planning to target United States economic interests including gas/oil pipelines, power generating dams and strike ships/oil tankers through explosive laden speed boats in International waters.”

One U.S. intelligence official told The Daily Beast that Mauritani is under intense interrogation from the ISI’s directorate T, the counterterrorism division that has in recent years been more cooperative than other elements of the ISI that are suspected of keeping important information about al Qaeda from their counterparts in the U.S. government. It is still being determined whether he’s giving good information.

Another U.S. official said, “The U.S. government is trying to tap all resources, including partnerships abroad including Pakistan and most prominently those in Pakistan who are questioning Mauritani and two of his cohorts.” Two U.S. intelligence officials said the threat connected to the 9/11 anniversary was ordered personally by Zawahiri.

Two of the U.S. officials who spoke to The Daily Beast also said the three individuals were supposed to connect with more facilitators already in the United States. One intelligence official described these facilitators as “muscle” for an operation.

At issue is an unconfirmed threat to New York and Washington that three operatives for al Qaeda are planning possible car bombs or a train attack to coincide with the 10th anniversary of the 9/11 attacks. Two of the operatives are believed by U.S. intelligence officials to be American citizens. The initial source of the information was a human agent close to al Qaeda and its allied organizations who travels between Pakistan and Afghanistan.

“The current belief is that two are U.S. citizens and the working assumption is that they are inside the United States,” one U.S. official said. That was the working assumption until Saturday afternoon. Another U.S. official, however, said there was no confirming intelligence that the two American citizens were inside the United States. All officials stressed the fragmentary nature of the threat information to date.

Two U.S. officials also said the three individuals were supposed to connect with more facilitators already in the United States. One intelligence official described these facilitators as “muscle” for an operation.

While the initial threat reports said an attack was planned to coincide with the 9/11 anniversary, one U.S. intelligence official said al Qaeda could be looking at other dates for an attack as well. Those dates, according to this source, include Oct. 7, the 10th anniversary of the invasion of Afghanistan; and Dec. 9, the 10th anniversary of when the Taliban government fell to coalition forces.