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.

Those freed include some Americans, while other U.S. nationals were unaccounted for, U.S. officials said.

The United States was evacuating 10 to 20 people caught up in the crisis, a U.S. defense official told CNN on Friday. They were to be taken to U.S. facilities in Europe, where their condition would be assessed, the official said.

Britain has sent trauma experts and consular affairs officers who can issue emergency passports to a location about 450 kilometers (280 miles) away from the plant, a Foreign Office official said, so they'll be "as close" as possible to the scene.

BP, which helps operate the gas field, said Friday that a "small number of BP employees" were unaccounted for. The same held for some workers with Statoil, though nine others with the company -- including five who escaped -- were safe. Four Norwegians and a Canadian with that oil firm were in an airport hotel in Bergen, Norway, after being taken from Algeria, Statoil spokeswoman Sissel Rinde said.

Both BP and Statoil -- two of the foreign companies with In Amenas operations -- were pulling their personnel out of Algeria, which is Africa's largest natural gas producer and a major supplier of natural gas to Europe.

BP said it had flown 11 of its employees and several hundred staffers from other companies out of the North African country Thursday and was planning another flight Friday.

Mark Cobb, a Texan who has a LinkedIn profile identifying him as general manager for a BP joint venture out of In Amenas, said he had escaped on the first day and was safe.

A U.S. military C-130 plane flew 12 people who were wounded in the ordeal out of Algeria on Friday, a U.S. defense official said. None of them were Americans, though efforts continue to evacuate freed Americans.

Three workers for a Japanese engineering company that was working on the site have been contacted and are safe, said Takeshi Endo, a senior manager for JGC Corp. But the company had not been able to contact 14 others, he said.

France's foreign ministry said that, in addition to one death, three of its citizens were rescued.

Japan 'terribly disappointed' in Algerian military operation

Algeria faces tough questions from governments of the kidnapped nationals over its handling of the crisis. Neither the United States nor Britain, for instance, was told in advance about Algeria's military operation Thursday.

Japanese Chief Cabinet Secretary Yoshihide Suga said his nation's officials had urged Algeria's government to avoid exposing hostages to danger. "We are terribly disappointed about the Algerians' military operation," Suga said.

Japanese Vice Minister Shunichi Suzuki summoned Algeria's ambassador Friday to express Tokyo's concern.

U.S. officials made a similar plea to the Algerians, urging them to be cautious and make the hostages' safety their priority, an official in President Barack Obama's administration said.

A senior U.S. official said American officials did not trust information they got from the Algerians, "because we hear one thing and then we hear something else."

But Algeria acted out of a sense of urgency after noticing hostages being moved toward "a neighboring country," where kidnappers could use them "as a means of blackmail with criminal intent," Communications Minister Mohamed Said told state television.

Algerian troops fired on at least two SUVs trying to leave the facility, Algerian radio said. And a reporter saw clashes near the site, according to the Algerian Press Service and radio reports.

"There were a number of dead and injured, we don't have a final figure," the communications minister said of casualties after the operation.

Belmoktar, the man behind the group claiming responsibility for the attack and kidnappings, is known for seizing hostages.