The hostage crisis in eastern Algeria is over, but the questions remain.
Among them, exactly how many people are unaccounted for at a remote natural gas facility after three days of chaos that ended Saturday, leaving at least 23 hostages and dozens of Islamist militants dead.
Some 685 Algerian workers and 107 foreigners were freed, the Algerian Interior Ministry said.
Britain's BP said Sunday four of its workers remain unaccounted for. And Norway's Statoil said five of its employees were missing, while 12 others are now home in Norway, Algeria and Canada.
"Search efforts are ongoing at the gas installation, looking for more possible victims. I fear the numbers will be updated with more victims later today when the search operation is expected to end," said Mohammed Said, Algeria's communication minister.
The attackers came from six countries -- only three were Algerian -- and included Arabs and Africans, Said told state-run Radio Algeria. Algeria's military found numerous "foreign military uniforms" in its sweep of the In Amenas facility, its Interior Ministry said.
Mauritania's Sahara Media news agency said Sunday it had a video from Moktar Belmoktar, who leads the Al-Mulathameen Brigade associated with al Qaeda in the Islamic Maghreb that regional media have reported was behind the attack.
In it, Belmoktar said, "We at al Qaeda are claiming responsibility of this blessed guerrilla operation."
Belmoktar has communicated with this and other news sites before, said Andrew Lebovich, a Senegal-based security analyst. But the news agency did not post the video, and CNN has not independently confirmed its authenticity.
Eleven former hostages -- among them British citizens -- have gotten medical treatment and psychological counseling from the U.S. military at a U.S. naval base in Sigonella, Italy, a U.S. official said Sunday. The hostages were brought from Algeria to the base Friday, the official said, and are being flown to their home countries as their conditions warrant. The remains of one American hostage were also brought to the base, the official said.