Washington:
One American was killed and two escaped unharmed from a remote Algerian natural gas plant stormed by armed militants, NBC News reported on Friday, noting that the fate of two others was unknown.
The five Americans were among dozens of hostages the attackers seized during their assault on the In Amenas plant in eastern Algeria on Wednesday, NBC said, citing US officials.
US officials had earlier declined to return multiple requests for comment about the hostages, including their number.
One American who escaped -- Mark Cobb -- told CNN via text messages that he was "safe" after escaping with some Algerian staff.
The Al-Qaeda-linked gunmen group known as "Signatories in Blood" want an end to the French intervention in neighboring Mali, according to Mauritania's ANI news agency, which quoted sources close to their leader, Mokhtar Belmokhtar.
ANI said Belmokhtar, a veteran Algerian extremist with Al-Qaeda ties who has claimed responsibility for the attack, also proposed exchanging the US hostages for the Egyptian blind sheikh Omar Abdul Rahman and Pakistani Aafia Siddiqui, jailed in the United States on charges of terrorist links.
The gunmen said they were still holding three Belgians, two Americans, one Japanese and a Briton, although Belgium said there was no indication any of its nationals were being held. An Algerian security official put the number of hostages at 10.
More workers remain unaccounted for, and the fate of at least 10 Japanese nationals and eight Norwegian hostages was still unknown.
Algerian news agency APS quoted a government official as saying the kidnappers, who claimed to have come from Niger, were heavily armed with machine guns, assault rifles, rocket launchers and missiles.
International criticism has been mounting for the haste with which Algeria launched a dramatic military assault to rescue the hostages, after an Algerian security official said it had left dead 12 hostages and 18 kidnappers.