US troops fired on a bus convoy of Shi'ite activists heading to Baghdad to take part in a demonstration against Israel's attack on Lebanon yesterday, an interior ministry official said. Both the official and a representative of radical cleric Moqtada Al Sadr's movement said one protester was killed and at least 16 injured in the shooting, although a US spokesman was unable to confirm or deny this. Injured Shi'ites brought to a hospital in Baghdad also said that one person had died, but were not clear on exactly what had happened in the incident on the road leading from the holy city of Najaf north to Baghdad. "The Americans opened fire on demonstrators going to Baghdad from Najaf to take part in the protest," said Sahib Al Amiri, general director of the Foundation for God's Martyrs, part of Sadr's movement. Amiri said the protesters were unarmed, but the interior ministry official said they had been accompanied by armed escorts from Sadr's Mehdi Army militia.