Algiers, Algeria (CNN) -- Some of the foreigners taken hostage by Islamist militants at an Algerian gas plant have been freed in an operation by the Algerian army, the country's state-run news agency reported Thursday, but there are reports of casualties.
The operation freed two Britons, a Kenyan and a French citizen, the Algerian Press Service said. The report also said there are a number of casualties in the action, but the exact number is not yet known. CNN could not independently confirm the report. CNN affiliate BFM-TV reported the French citizen is a nurse who worked on the site.
An Irish hostage is also free, the Irish government said, but it is not clear if he was freed by the Algerian military effort.
"The kidnap ordeal of Belfast man, Stephen McFaul, has ended," said the taoiseach, or Irish prime minister, Enda Kenny. "I am greatly relieved to hear that Stephen is safe and well. I believe he has already spoken to his family in Belfast and I wish him a safe return home to his loved ones."
An unspecified number of Americans are among the hostages held by terrorists at a BP facility in Algeria, White House spokesman Jay Carney said Thursday as he condemned the attack "in the strongest terms."
"We are closely monitoring the situation," he said. "We are in contact with Algerian authorities and our international partners as well as BP security office in London. Unfortunately, the best information that we have at this time, as I said, indicates that U.S. citizens are among the hostages. But we do not have, at this point, more details to provide to you. We are certainly concerned about reports of loss of life and we are seeking clarity from the government of Algeria."
Algerian troops fired on two SUVs trying to leave the kidnapping site, Algerian radio said, citing local sources. An Algerian reporter saw heavy clashes near the site, APS and radio reports said.
The kidnappers have AK-47 firearms and put explosive-laden vests on some of the hostages, a State Department official said. It is not clear whether the hostage-takers wore the suicide vests when they staged the action, but they did put them on some of the hostages, another U.S. official said.
"Situation remains very serious and difficult," said a Twitter message from the British prime minister's office.
