Ayman al-Zawahiri, Al-Qaeda's long-time number two, has vowed in a video eulogy to Osama bin Laden that he will pursue his late leader's jihad against the West, SITE Intelligence Group reported on Wednesday.
"We will pursue the jihad until we expel the invaders from Muslim lands," he was quoted as saying in the eulogy to bin Laden who was killed in a US raid in Pakistan on 2 May.
"The man who terrified America in his life will continue to terrify it after his death," he added in the video message titled "The Noble Knight Dismounted," which SITE said was posted on jihadist online forums on Wednesday.
"You will continue to be troubled by his famous vow: You shall not dream of security until we enjoy it and until you depart the Muslims' lands," added the Egyptian militant, who was in white garb and a turban with a machinegun behind him.
He vowed to make sacrifices needed to "deprive America of security."
Zawahiri also vowed allegiance to the leader of Taliban, Mullah Omar.
"We renew our allegiance to the leader of the believers, Mullah Mohammad Omar," said Zawahiri speaking of the one-eyed leader who has a $10-billion US bounty on his head.
"We promise him obedience... in jihad for Allah and to set up sharia (Islamic) law," he added.
Last month, the Taliban fiercely denied Omar had died after an Afgan intelligence source called a handful of reporters to tell them that he had been killed by Pakistan's Inter-Services Intelligence agency.
The claims came exactly three weeks after the killing of bin Laden by US Navy SEALs in Pakistan and amid a fierce wave of targeted attacks as the Taliban said it was launching a spring offensive.
In an audio message on 22 May, Zawahiri backed the wave of Arab revolts and called for sharia Islamic law to be applied in Egypt.
But he warned Libyans the NATO-led aerial bombing campaign against Muammar Gaddafi seeks to replace the strongman with its own tyrannical regime.