On Monday, Philippine Foreign Affairs officials said six Filipinos were among the hostages killed. Spokesman Raul Hernandez told reporters that 16 Filipinos have been accounted for and four others are still missing.
The dead hostages were also known to include at least one American and French workers. Nearly two dozen foreigners by some estimates were unaccounted for.
It was unclear whether anyone was rescued in the final assault on the complex, which is run by the Algerian state oil company along with BP and Norway's Statoil.
Two private Algerian TV stations and an online news site said security forces scouring the plant found five militants hiding out and learned that three others had fled. That information could not be immediately confirmed by security officials.
Authorities said the bloody takeover was carried out Wednesday by 32 men from six countries, under the command from afar of the one-eyed Algerian bandit Moktar Belmoktar, founder of the Masked Brigade, based in Mali. The attacking force called itself "Those Who Sign in Blood."
The Masked Brigade said Sunday the attack was payback against Algeria for allowing over-flights of French aircraft headed to Mali and for closing its long border with Mali. In an earlier communication, the Brigade claimed to have carried out the attack in the name of al-Qaida.
Armed with heavy machine guns, rocket launchers, missiles and grenades, the militants singled out foreign workers at the plant, killing some of them on the spot and attaching explosive belts to others.
Algeria's tough and uncompromising response to the crisis was typical of its take-no-prisoners approach in confronting terrorists, favoring military action over negotiation. Algerian military forces, backed by attack helicopters, launched two assaults on the plant, the first one on Thursday.
The militants had "decided to succeed in the operation as planned, to blow up the gas complex and kill all the hostages," Algerian Communications Minister Mohamed Said told state radio.