DAVOS - Iraqi Prime Minister Prime Minister Haider al-Abadi said on Thursday that three Americans who disappeared in Iraq last week "just went missing," and he very much doubted any Iranian involvement.Asked by a pool reporter at the start of a meeting with US Secretary of State John Kerry in Davos if he thought there was an Iranian link to their disappearance, Abadi said:"I don't know about that. I doubt it very much. We don't know if they have been kidnapped ... They just went missing."Iraqi intelligence and US government sources said on Tuesday the three US citizens were kidnapped and were being held by an Iranian-backed Shi'ite militia.Unknown gunmen seized the three on Friday from a private residence in the southeastern Dora district of Baghdad, Iraqi officials say. They are the first Americans to be abducted in Iraq since the withdrawal of US troops in 2011.The US sources said Washington had no reason to believe Tehran was involved in the kidnapping and did not believe the trio were being held in Iran, which borders Iraq.