BAMAKO, Mali -- Without warning other governments, Algeria mounted an assault Thursday on the heavily armed fighters holding American and other hostages at a remote Sahara gas field facility, freeing captives and killing kidnappers but also leaving some of the hostages dead and foreign leaders scrambling to find out the fates of citizens trapped inside.
Hours after the raid, there was still no official word on the number of hostages who were freed, killed or still held captive. Estimates of the foreign casualties ranged from four to 35, though one Algerian official said the high figure was "exaggerated."
Despite requests for communication and pleas to consider the safety of their abducted citizens, the United States, Britain and Japan said they had not been told in advance about the military assault, stirring frustration that the Algerians may 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 to deal forcefully with the kidnappers. "Those who think we will negotiate with terrorists are delusional," Communications Minister Mohand Said Oublaid said in an announcement about the assault on the facility near In Amenas, in eastern Algeria, close to the Libyan border. "Those who think we will surrender to their blackmail are delusional."
The midday assault came more than 24 hours after a militant group, which the Algerians said had ties to jihadis in the region, ambushed a bus carrying gas-field workers to a nearby airport and then commandeered the compound. It was one of the boldest abductions of foreign workers in years.
The abductions were meant to avenge France's armed intervention in neighboring Mali, Mr. Oublaid said, a conflict that has escalated since French warplanes began striking Islamist fighters who have carved out a vast haven there.
Algeria's Interior Minister Daho Ould Kablia said the gas field seizure had been overseen by Mokhtar Belmokhtar, an Algerian who reportedly established his own group in the Sahara after falling out with other local al-Qaida leaders. The description of the leader was one of the most specific pieces of information the Algerians gave on a tense day of vague and contradictory accounts of the abduction and raid.
The U.S. became more deeply involved in the Mali war Thursday, working with the French to determine how best to deploy U.S. C-5 cargo planes to ferry French troops and equipment into the country, a U.S. military official said. The United States has long been wary about stepping more directly into the Mali conflict, worried that it could provoke precisely the kind of anti-Western attack that occurred in Algeria, with deadly consequences.
After the raid to free the hostages, the Algerians acknowledged a price had been paid. "The operation resulted in the neutralization of a large number of terrorists and the liberation of a considerable number of hostages," Mr. Oublaid said. "Unfortunately, we deplore also the death of some, as well as some who were wounded."
Algerian national radio described a scene of pandemonium and high alert at the public hospital in the town of In Amenas, where wounded and escaped hostages were sent. The hospital director, Shahir Moneir, said in the report that wounded foreign hostages were transferred to the capital, Algiers.
In a phone interview from the hospital, one Algerian who had been held captive, who identified himself as Mohamed Elias, said some hostages had exploited the chaos created by the Algerian military assault to flee.
Senior U.S. military officials said aides traveling in London with Defense Secretary Leon Panetta were struggling to get basic information about the raid, and that an unarmed U.S. Predator drone was monitoring the gas-field site. The senior official said possibly seven to eight Americans were among the hostages -- the first official indication of the number of Americans involved -- and that he did not know if any had been killed in the raid.
British Prime Minister David Cameron said his office had not been told ahead of time, an implicit criticism of the Algerian government. A spokesman said Mr. Cameron had learned of the raid through Britain's own intelligence sources, and that "the Algerians are aware that we would have preferred to have been consulted in advance."
Japan also expressed strong concern, saying Algeria had failed not only to advise of the operation ahead of time, but also to heed its request to halt the operation because it was endangering the hostages.
The situation is "very confused," French President Francois Hollande said at a Paris news conference and was "evolving hour by hour." He gave France's first official confirmation that its citizens were among the captives.