Al-Qaeda Friday vowed to avenge the death of Osama bin Laden and urged Muslims to rise up against the United States, as rallies against the killing of the 9/11 mastermind in a US raid flared in the Islamic world. \"We call upon our Muslim people in Pakistan, on whose land Sheikh Osama was killed, to rise up and revolt to cleanse this shame,\" the terror network said in a statement released by the SITE monitoring group. Confirming bin Laden\'s death for the first time, Al-Qaeda urged Pakistani Muslims \"to cleanse their country from the filth of the Americans who spread corruption in it.\" In the statement posted on jihadist Internet forums, the Islamist group proclaimed its Saudi-born founder a \"martyr,\" adding he had \"terrified all the nations of disbelief.\" The White House swiftly said it was on alert for security threats as Al-Qaeda also vowed to release an audio tape made by their inspirational leader just a week before he was shot dead on Monday by US commandos in Pakistan. \"We are quite aware of the potential for activity and are highly vigilant on that matter for that reason,\" said White House spokesman Jay Carney. US President Barack Obama was Friday to meet privately with members of the elite commando team who carried out the risky helicopter-borne raid of the fortified compound in the Pakistani town of Abbottabad where bin Laden had been hiding. The meeting comes a day after Obama laid a wreath at Ground Zero, the site where the felled World Trade Center once stood, in a somber moment aimed at bringing closure to Americans still haunted by the September 11, 2011 attacks.