SITE Intelligence Group, which monitors videos from radicals, posted one showing al-Nigiri with what appeared to be an explosive belt around his waist.
The Algerians' use of forced raised an international outcry from some countries worried about their citizens.
But French Foreign Minister Laurent Fabius said Sunday on French television: "The terrorists ... they're the ones to blame."
David Plouffe, a senior adviser to President Barack Obama, said that al-Qaida and al-Qaida-affiliated groups remain a threat in North Africa and other parts of the world, and that the U.S. is determined to help other countries destroy those networks.Speaking on "Fox News Sunday," Plouffe said the tragedy in Algeria shows once again "that all across the globe countries are threatened by terrorists who will use civilians to try and advance their twisted and sick agenda." ___ Elaine Ganley and Lori Hinnant in Paris contributed to this report.