By AOMAR OUALI and PAUL SCHEMMALGIERS, Algeria (AP) â¿¿ The death toll from the terrorist siege at a natural gas plant in the Sahara climbed to at least 81 on Sunday as Algerian forces searching the refinery for explosives found dozens more bodies, many so badly disfigured it was unclear whether they were hostages or militants, a security official said. Algerian special forces stormed the plant on Saturday to end the four-day siege, moving in to thwart what government officials said was a plot by the Islamist militants to blow up the complex and kill all their hostages with mines sown throughout the site. The government said after the assault that at least 32 extremists and 23 hostages were killed. Then, on Sunday, Algerian bomb squads sent in to blow up or defuse the explosives found 25 bodies, said the security official, who spoke on condition of anonymity because of the sensitivity of the situation. "These bodies are difficult to identify. They could be the bodies of foreign hostages or Algerians or terrorists," the official said. In addition, a wounded Romanian who had been evacuated died, raising the overall death toll to at least 81. "Now, of course, people will ask questions about the Algerian response to these events, but I would just say that the responsibility for these deaths lies squarely with the terrorists who launched a vicious and cowardly attack," British Prime Minister David Cameron said. Three Britons were killed and another three were feared dead. The dead were also known to include American, Filipino and French workers. Algerian authorities said 685 of their citizens, the backbone of the workforce, escaped without saying how many may have died. More than two dozen foreigners 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.