ALGIERS, Algeria - More details are emerging about Thursday's raid by Algerian forces on a natural gas plant where militants had held foreign nationals for more than a day.

A U.S. official says some Americans among the workers escaped, some are still being held or unaccounted for.

Algerian helicopters and special forces stormed the plant in the stony plains of the Sahara on to wipe out Islamist militants and free hostages from at least 10 countries. Bloody chaos ensued, leaving the fate of the fighters and many of the captives uncertain.

Dueling claims from the military and the militants muddied the world's understanding of an event that angered Western leaders, raised world oil prices and complicated the international military operation in neighboring Mali.