Followers of Osama bin Laden flooded Islamic websites with pledges of allegiance, videos and pictures Saturday to mark the al-Qaeda leader's 50th birthday, reflecting his importance as a symbol even though he has not shown his face for years. One user, going by the name Abu Yacoub, posted an old picture of bin Laden wearing a helmet and khaki military uniform while carrying a two-way radio in a deserted area, possibly from his fight in Afghanistan against the Soviet Union two decades ago. "Osama bin Laden turns 50. God protect our leader, our Sheik Osama bin Laden. God reward him for his words and actions," Abu Yacoub wrote on a website commonly used by insurgents. Another message titled the "Manhattan invasion" featured old footage of the Sept. 11, 2001, attacks in the United States and the wills of the men who hijacked the planes. Another follower posted a poem of dedication to bin Laden. A spokesman for US troops in Afghanistan expressed disgust over the celebrations. "Instead of focusing on the anniversary of his birth, people around the world - and particularly the people here in Afghanistan - should take a moment to remember the innocent people who have been killed or injured by terrorist extremists like Osama bin Laden," said Maj. William Mitchell. Like most things involving bin Laden, his exact birth date is unknown. GlobalSecurity.org, a Virginia-based think tank, said bin Laden was either born March 10 or July 30 of 1957 in Riyadh, Saudi Arabia. The FBI just lists that he was born in 1957. Bin Laden is believed to be hiding in Afghanistan or the country's lawless border region with Pakistan. US-led coalition troops have conducted hundreds of unsuccessful operations in the region to find him. Intelligence officials have suggested that the trail for bin Laden has gone cold, and there has been speculation over whether he is dead or alive. The last time bin Laden appeared in a video was Oct. 29, 2004, in a warning to the U.S. that it would face another attack if it did not stop meddling in Arab and Muslim affairs. The al-Qaeda leader appeared pale and thinner in the video. A number of bin Laden audio tapes have been posted on Islamic websites since then, the latest in July, but his voice has sounded tired, fueling rumors that he was seriously ill. Bin Laden's deputy, Ayman al-Zawahri, meanwhile, has become more public, appearing in four messages since the beginning of the year and more than a dozen in 2006.