Pakistani security forces have arrested 40 people in Abbottabad suspected of having connections to Usama bin Laden.
Pakistani sources called the arrests near bin Laden's compound the "second phase" of the operation that killed the Al Qaeda leader, according to the Open Source Center.
This comes as Al Qaeda released a statement on Islamist websites confirming the death of bin Laden.
The statement, dated May 3, was the first by the terror network since bin Laden was killed Monday by U.S. commandos in a raid on his hideout in Abbottabad, Pakistan. The statement's authenticity could not be independently confirmed, but it was posted on websites where the group traditionally puts out its messages.
"We stress that the blood of the holy warrior sheik, Usama bin Laden, God bless him, is precious to us and to all Muslims and will no go in vain," the statement said. "We will remain, God willing, a curse chasing the Americans and their agents, following them outside and inside their countries."
"Soon, God willing, their happiness will turn to sadness," it said, "their blood will be mingled with their tears."
In the statement, Al Qaeda also called on the people of Pakistan -- "where Sheik Osama was killed" -- to rise up in revolt against its leaders. It also said that an audio message bin Laden recorded a week before his death would be issued soon.
The Associated Press contributed to this report.