More than 20 foreigners were captive or missing inside a desert gas plant on Saturday, nearly two days after the Algerian army launched an assault to free them that saw many hostages killed.The standoff between the Algerian army and al Qaeda-linked gunmen - one of the biggest international hostage crises in decades - entered its fourth day, having thrust Saharan militancy to the top of the global agenda.The number and fate of victims has yet to be confirmed, with the Algerian government keeping officials from Western countries far from the site where their countrymen were in peril. Reports put the number of hostages killed at between 12 to 30, with possibly dozens of foreigners still unaccounted for - among them Norwegians, Japanese, Britons, Americans and others.State Department spokeswoman Victoria Nuland confirmed on Friday the death of one American, Frederick Buttaccio, in the hostage situation, but gave no further details.Two Japanese, two Britons and a French national were among the seven foreigners confirmed dead in the army’s storming, the Algerian security source told Reuters. One British citizen was killed when the gunmen seized the hostages on Wednesday.A U.S. official said on Friday that a U.S. Medevac flight carrying wounded of multiple nationalities had left Algeria.By nightfall on Friday, the Algerian military was holding the vast residential barracks at the In Amenas gas processing plant, while gunmen were holed up in the industrial plant itself with an undisclosed number of hostages.Agencies