The fate of dozens of hostages seized by Islamist gunmen at a remote gas field in Algeria remained unclear early Friday, hours after the Algerian military stormed the site.

Estimates of the numbers killed in the showdown varied widely.

Algerian Communications Minister Mohamed Said Oublaid said a "large number of terrorists were neutralized" during the raid, according to the Voice of America.  He also said several hostages were killed.

​​A militant spokesman said 34 hostages and 15 kidnappers were killed when Algerian helicopters attacked. But other estimates were lower.

Fox News, citing Pentagon officials, reported that a Texan remains unaccounted for but two other Americans escaped unharmed Thursday. Five other Americans who had been at the vast complex were able to avoid capture when the terrorists first attacked early Wednesday.

Some of the hostages reportedly escaped from the natural gas pumping plant, near In Amenas, close to the border with Libya and 800 miles southeast of Algiers.

An unknown number of hostages left the country on a charter flight and were expected to land at London's Gatwick airport near midnight Thursday, according to BP, which operates the gas complex. The plane had not arrived as of 3:15 a.m. Friday.

Among the dozens unaccounted for were Americans, Britons, French, Norwegians, Romanians, Malaysians, Japanese and Algerians.

The Algerians acted alone. Despite requests for communication and pleas to consider the safety of their captive citizens, the United States, Britain and Japan told The New York Times they had not been told in advance about the assault and feared that the Algerians might have been overly aggressive and caused needless casualties.

But the Algerian government, which has a history of violent suppression of Islamist militancy, stood by its decision.

“Those who think we will negotiate with terrorists are delusional,” Oublaid said. “Those who think we will surrender to their blackmail are delusional.”

The Islamist militants who stormed the plant and workers' housing before dawn on Wednesday seizing up to 41 hostages claimed to be acting in support of Islamists fighting in neighboring Mali, as Mali's military tries to drive them out with the backup of French air and ground forces.

According to the AP, militants with the Masked Brigade, a Mali-based al Qaeda offshoot, provided updates through a Mauritanian news organization that said the Algerians attacked when the militants tried to move hostages from the energy complex. The group claimed that 35 hostages and 15 militants died but seven hostages survived the helicopter attack on its convoy.

Richard Cochrane, an analyst at London's IHS Jane's security and defense company, told the Voice of America the incident could have long-term economic implications for Algeria. 

He said the kidnappings have elevated the risks for foreign investors in the country. 

"Algeria is well aware that these sites were targets, which is why guards and the army were on station to respond to these events and the fact that they were unable to defend these workers is going to be a cause of severe embarrassment and perhaps a longer-term problem for Algerians persuading new investors into the country to work in these isolated southern regions," he said.