A rescue mission at an Algerian gas plant has resulted in the death of 12 hostages, according to state news, while military sources claim at least 30 casualties. Dozens of foreigners remain unaccounted for amid reports that the siege has ended. A massive fire has been spotted late on Friday at the huge gas plant where many of the missing hostages are still believed to be held. Militants are believed to still be in control of the gas plant, while the residential premises housing hundreds of workers were recaptured by the government forces in the rescue operation, said Norway's Prime Minister Jens Stoltenberg, eight of whose countrymen are missing. Conflicting reports of foreign and Algerian hostage casualties during the army's three-day rescue operation make it unclear whether this is the total death toll or should be added to the previous total of 30, also reported by state news. Algerian news outlet APS says that nearly 650 hostages have been freed, among them 573 Algerians and 100 of the 132 foreigners being held. At least one American has been killed in the standoff, but it is still unclear how he died. The body recovered Friday was identified as Frederick Buttaccio of Texas, US State Department confirmed.