At least 20 Shia pilgrims have been found shot dead in western Iraq, reports quoting Iraqi officials say.The group were reportedly travelling by bus to visit a shrine in Syria when they were held up at a checkpoint in a remote desert area of Anbar province. Police general Haider Rzayj said the armed men had ordered the pilgrims off the bus and killed them with automatic weapons. Attacks on Shia pilgrims have claimed hundreds of lives in recent months. The gold-domed al-Askari mosque was largely destroyed in a massive bombing in 2006, an attack blamed for starting the 2006-07 wave of sectarian bloodshed.Levels of violence in Iraq have fallen since the peak of those years, but militants still carry out almost daily strikes.