In a video posted on a social media website, longtime al-Qaida Ayman al-Zawahri vowed to press ahead with al-Qaida's campaign against the United States and its allies."The sheikh has departed, may God have mercy on him, to his God as a martyr and we must continue on his path of jihad to expel the invaders from the land of Muslims and to purify it from injustice," Zawahri said.The 28-minute clip is Egyptian-born Zawahri's first public response to the killing of Osama bin Laden. He warns the US of a Muslim rebellion."Today, thanks be to God, America is not facing an individual or a group ... but a rebelling nation which has awoken from its sleep in a jihadist renaissance challenging it wherever it is," he said in the clip. Zawahri warned Americans not to rejoice at bin Laden's death, praised the uprisings in his native Egypt and other Arab countries, and called on Pakistan to follow suit.