KHARTOUM (Reuters) - A man threw his shoe at Sudanese President Omar Hassan Al-Bashir in a public conference in the capital on Monday, a particularly insulting action in Arab culture, eye-witnesses said. They said the unidentified man was swiftly detained by about 10 presidential guards although the projectile missed Bashir. It was not immediately clear why the man hurled his shoe. The presidency denied any shoe was thrown and said the man was stopped by security while carrying an envelope he wanted to deliver to Bashir. In Arab culture, it is rude even to show the sole of your shoe to a colleague and shoes are left at the door of mosques. Former US President George W Bush was subjected to the same insult in Iraq in 2008 when an Iraqi journalist threw both his shoes at him. The man was close to the podium and threw the shoe but it didnt reach him, said one eye-witness, saying the incident appeared to shock the dozens of officials gathered for the conference on strategic planning for governing Sudan. Three eye-witnesses who had been inside the Friendship Hall in Khartoum, all of whom asked not to be named, confirmed the incident to Reuters. They said the man was in his late 40s or early 50s, was dressed smartly and said nothing. He seemed calm, even after he was arrested, said another of the witnesses. Witnesses said journalists at the event had recording equipment and cameras taken from them by security after the incident. Presidential spokesman denied the shoe incident, saying: The man just wanted to give the president a note... but was intercepted by the security.