WASHINGTON (AP) — The Obama administration said Friday it was trying to secure the release of Americans still being held by militants on the third day of a standoff at a natural gas complex in the Sahara, and pressed Algeria's government to ensure that hostages aren't sacrificed in a zealous attempt to free them.

Secretary of State Hillary Rodham Clinton said she spoke by telephone with Algerian Prime Minister Abdelmalek Sellal to get an update on Americans and others in danger at the sprawling Ain Amenas refinery 800 miles south of Algiers. She said the "utmost care must be taken to preserve innocent life."

Clinton spoke after the State Department confirmed that Americans were still being held hostage, even as some Americans were being flown out of the country for recovery in Europe. The Algerian state news agency reported that 12 hostages had been killed since Wednesday's start of an Algerian rescue operation, and world leaders steadily increased their criticism of the North African country's handling of the attack.