After three days of chaos, drama and an unknown number of deaths, Algerian special forces troops were holding their fire Saturday in the hostage crisis at a gas facility in the nation's remote eastern desert.

Survivors described harrowing escapes from Islamic militants who attacked the site early Wednesday. Some invented disguises, others sneaked to safety with locals, and at least one ran for his life with plastic explosives strapped around his neck.

Six Americans were freed or escaped, a U.S. official told CNN. The official provided no other information about their status or whereabouts. Other Americans were unaccounted for. Earlier Friday, State Department spokeswoman Victoria Nuland said there were still American hostages.

Yet others didn't make it -- either because they were killed or were still being held.

Algerian troops staged a military offensive that some nations criticized as endangering the lives of the hostages.

On Friday evening, they were trying a different tack, the state-run Algerian Press Service reported.

"The special forces ... are still seeking a peaceful settlement before neutralizing the terrorist group currently entrenched in the refinery, and free a group of hostages who are still detained," it said.

It was not clear how many hostages were seized by the Islamist militants and how many were being held. Thursday's military operation ended with 650 hostages -- including 100 foreigners -- freed, while at least 12 Algerian and foreign workers were killed, the Algerian Press Service reported in what it said was a "provisional toll."

In addition, 18 of the attackers were "neutralized," APS said.

The dead include one American, identified as Frederick Buttaccio, Nuland said, as well as one French and a Briton.

At least 30 foreign workers were unaccounted for, according to the official media report.

British Prime Minister David Cameron said Friday that significantly fewer than 30 of his countrymen remained hostage. There could be as few as three Americans still being held, two U.S. officials said earlier this week.

The fate of eight workers with Norway's Statoil, some of them Norwegians, was unclear, the company said. The same was true for the 14 Japanese unaccounted for, Chief Cabinet Secretary Yoshihide Suga told reporters in Tokyo. And Malaysia's state-run news agency, citing its foreign ministry, reported Thursday two of its citizens were held captive.

A spokesman for Moktar Belmoktar, a veteran jihadist who leads the Brigade of the Masked Ones -- a militant group associated with al Qaeda in the Islamic Maghreb -- reportedly offered to free U.S. hostages in exchange for two prisoners.

The prisoners are Sheikh Omar Abdel Rahman, who orchestrated the 1993 World Trade Center bombing, and Aafia Siddiqui, a Pakistani woman jailed in the United States on terrorism charges, the spokesman said in an interview with a private Mauritanian news agency.

Asked Friday about the offer, State Department spokeswoman Nuland rejected it, restating U.S. policy of not negotiating with terrorists.

"This is an act of terror," U.S. Secretary of State Hillary Clinton said Friday. "The terrorists ... are the ones who have assaulted this facility (and took) hostage Algerians and others (from) around the world who were going about their daily business."

A dangerous escape

The incident began when the militants -- apparently angry about Algeria's support in a rout of their comrades in neighboring Mali -- targeted the gas field, which is operated by Algeria's state oil company in partnership with foreign companies.

At the start of the siege, the militants gathered the Westerners into a group and tied them up, survivors said.

The kidnappers were equipped with AK-47 rifles and put explosive-laden vests on some hostages, a U.S. State Department official said.

Some escaped by disguising themselves, according to Regis Arnoux, who runs a catering firm at the site and had spoken with some of his 150 employees who were freed. He said they all were traumatized.

Some Algerian hostages were free to walk around the site but not to leave, Arnoux said. Still, a number of them escaped, he said.

As the Algerian military launched its operation Thursday, the militants moved some hostages, according to one survivor's account.

With plastic explosives strapped around their necks, these captives were blindfolded and gagged before being loaded into five Jeeps, according to the brother of former hostage Stephen McFaul.

McFaul, with the explosives still around his neck, escaped after the vehicle he was in -- one of several targeted by Algerian fighters -- crashed, his brother said from Belfast, Northern Ireland.

"I haven't seen my mother move as fast in all my life, and my mother smile as much, hugging each other," Brian McFaul said upon his family hearing his brother was safe. "... You couldn't describe the feeling."

McFaul said the other four Jeeps were "wiped out" in an explosion, and his brother believed the hostages inside did not survive.

Nations mobilize to help citizens caught up in crisis

U.S. Defense Secretary Leon Panetta, speaking in London, said the United States was working round the clock to ensure the safe return of its citizens.