Since the crisis ended, international leaders, including those of countries whose nationals were killed in the hostage-taking, have expressed support for how the Algerian authorities handled the crisis. Previously, some governments had expressed frustration at the fact that they had not been informed prior to Algerian forces' moving in.

French President Francois Hollande said that, though the details of the assault were not yet known, it was clear that negotiations with the hostage-takers were not possible, and that Algeria had responded in the "most suitable" way.

British Prime Minister David Cameron said there was "no justification for taking innocent life" as the extremists had.

In his first public comment on the issue, US President Barack Obama placed the blame for the crisis squarely on "the terrorists who carried it out." In a statement released by the White House, Obama condemned the hostage-taking in the "strongest possible terms," adding that Washington would "continue to work closely with all of our partners to combat the scourge of terrorism in the region, which has claimed too many innocent lives."

One American is among the 23 hostages killed in the deadly siege. Thirty-two others described by the authorities as "terrorists" were also killed. Also among the dead are French and British nationals.

Algeria's state news agency, though, reported that despite the fact that so many hostages lost their lives, the security forces' operation had been an overwhelming success.

"This intervention resulted in the release of 685 Algerian employees and 107 foreigners," the APS quoted an Interior Ministry source as saying.

The Algiers-based newspaper El Watan reported, however, that the Islamist hostage-takers had killed seven of the hostages during the final assault by Algerian troops.

Several hours after the hostage-taking had ended, many of the hostages remained unaccounted for, including employees of BP, which is one of the partners at the In Amenas natural gas extraction complex as well as workers for Norway's Statoil.

Early on Sunday, Japanese Prime Minister Shinzo Abe said that he had received "somber information" about Japanese nationals also caught up in the drama at In Amenas.

The group that claimed responsibility for the kidnappings has said the operation was launched in retaliation for France's military intervention in neighboring Mali. President Hollande has said that troops would remain in Mali as long as needed "to defeat terrorism" in the country. France already has 2,000 troops on the ground in Mali - of a maximum of 2,500 pledged for the mission.

pfd/jlw (AFP, Reuters, dpa)