The bloody three-day hostage standoff at a natural gas plant in the Sahara took a dramatic turn Friday as Algeria's state news service reported that nearly 100 of the 132 foreign workers kidnapped by Islamic militants had been freed.

That number of hostages at the remote desert facility was significantly higher than any previous report, and still meant that the fate of over 30 foreign energy workers was unclear. Yet it could indicate a potential breakthrough in the confrontation that began when the militants seized the plant early Wednesday.

The desert siege erupted when militants attempted to hijack two buses at the plant, were repulsed, and then seized the sprawling refinery, which is 1,300 kilometres south of Algiers. They had claimed the attack came in retaliation for France's recent military intervention against Islamist rebels in neighbouring Mali, but security experts have said it must have taken weeks of planning to hit the remote site.

The Canadian government says it's aware of published reports that the Islamic militants who seized scores of hostages at a remote Algerian gas plant may include a Canadian.

In a report Thursday, Mauritania's state-owned ANI news agency said the hostage-takers came from Algeria, Canada, Mali, Egypt, Niger and Mauritania.

"We are aware of reports that a Canadian may have been involved in the hostage-taking in Algeria," Department of Foreign Affairs spokeswoman Chrystiane Roy said.

Unidentified rescued hostages in Ain Amenas, Algeria, in an image taken from television Friday Jan. 18. (Canal Algerie/Associated Press)

"We are pursuing all appropriate channels to seek further information and are in close contact with Algerian authorities," Roy told CBC News.

Meanwhile, a Canadian who was among the employees at the facility when the attack was launched on Wednesday is safe.

U.S. officials said Friday that one American worker at the complex, Texas resident Frederick Buttaccio, has been found dead there, but that it was unclear how he died. The Obama administration was seeking to secure the release of other Americans still being held by the militants.

France said a French citizen was killed during the raid by Algerian forces. The Foreign Ministry identified him as Yann Desjeux, without providing additional information. The ministry said three other French hostages are now free, but didn't say if any French citizens remain in captivity.

The militants, trapped in the main refinery area on Friday, offered to trade two captive American workers for two terror figures jailed in the United States, according to a statement received by a Mauritanian news site that often reports news from North African extremists.

Those terror figures sought include Omar Abdel Rahman, the blind sheikh who was convicted of plotting to blow up New York City landmarks and considered the spiritual leader of the 1993 World Trade Center bombing, and Aafia Siddiqui, a Pakistani scientist convicted of shooting at two U.S. soldiers in Afghanistan.

The news agency also reported Friday that 12 hostages, including Algerians and foreign workers, have died since Wednesday. Citing an unnamed source, the APS news agency also reported that 18 hostage-takers have been killed.

It was not clear whether the remaining foreigners were still captive or had died during the Algerian military offensive to free them that began Thursday.

Since then, Algeria's government has kept a tight grip on information. It wasn't clear how the government arrived at the latest tally of hostages, which was far higher than the 41 foreigners the militants had claimed as hostages.

Secretary of State Hillary Rodham Clinton speaks about the situation in Algeria in Washington, Friday, Jan. 18, 2013. (Susan Walsh/Associated Press)

The militants had seized hundreds of workers from 10 nations at Algeria's remote Ain Amenas natural gas plant. The overwhelming majority were Algerian and were freed almost immediately.

The Algerian forces retaliation on Thursday left leaders around the world expressing strong concerns about the safety of the hostages. Strong concerns have been expressed by world leaders in the past few days about how Algeria was handling the situation and its apparent reluctance to communicate.

U.S. Secretary of State Hillary Clinton told Algeria to do everything possible to protect the hostages.

Clinton spoke with Algerian Prime Minister Abdelmalek Sellal on Friday and underscored that "the utmost care must be taken to preserve innocent life."

The attack, she said, was an "act of terror." She also vowed greater U.S.-Algerian counterterrorism co-operation in future.

U.S. Defence Secretary Leon Panetta said there would be "no place to hide" for anyone who looks to attack the United States.

"Terrorists should be on notice that they will find no sanctuary, no refuge, not in Algeria, not in North Africa, not anywhere," Panetta said Friday.

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Workers kidnapped by the militants came from around the world — Americans, Britons, French, Norwegians, Romanians, Malaysians, Japanese, Algerians.

Terrorized hostages from Ireland and Norway trickled out of the Ain Amenas plant. BP, which jointly operates the plant, said it had begun to evacuate employees from Algeria.

"This is a large and complex site and they are still pursuing terrorists and possibly some of the hostages," British Prime Minister David Cameron said Friday in London.

He told British lawmakers the situation remained fluid and dangerous, saying "part of the threat has been eliminated in one part of the site, a threat still remains in another part."

With files from CBC News