The French military assault on Islamist extremists in Mali escalated into a potentially much broader North African conflict on Wednesday when, in retribution, armed attackers in unmarked trucks seized an internationally managed natural gas field in neighboring Algeria and took at least 20 foreign hostages, including Americans.
Algerian officials said at least two people, including a Briton, were killed in the assault, which began with a predawn ambush on a bus trying to ferry gas-field workers to an airport. Hundreds of Algerian security forces were sent to surround the gas-field compound, creating a tense standoff, and the country's interior minister said there would be no negotiations.
Algeria's official news agency said at least 20 fighters had carried out the attack and mass abduction. There were unconfirmed reports late on Wednesday that the security forces had tried to storm the compound and had retreated under gunfire from the hostage takers.
Many details of the assault on the gas field in a barren desert site near Libya's border remained murky, including the precise number of hostages, which could be as high as 41, according to claims by the attackers quoted by regional news agencies. American, French, British, Japanese and Norwegian citizens who worked at the field were known to be among them, officials said.
Defense Secretary Leon E. Panetta called the gas-field attack a terrorist act and said the United States was weighing a response. His statement suggested that the Obama administration could be drawn into a military entanglement in North Africa that it had been seeking to keep at arm's length — even as it has conceded that the region has become a new haven for extremists who threaten Western security and vital interests.
"I want to assure the American people that the United States will take all necessary and proper steps that are required to deal with this situation," Mr. Panetta said during a visit to Italy.
The gas-field attack, which seemed to take foreign governments and the British and Norwegian companies that help run the facility completely by surprise, appeared to make good on a pledge by the Islamist militants who seized northern Mali last year to sharply expand their struggle against the West in response to France's military intervention that began last week.
The hostage taking potentially broadened the conflict beyond Mali's borders and raised the possibility of drawing an increasing number of foreign countries into direct involvement, particularly if expatriates working in the vast energy extraction industries of North Africa become targets. It also doubled, at least, the number of non-African hostages that Islamist militants in northern and western Africa have been using as bargaining chips to finance themselves in recent years through ransoms that have totaled millions of dollars.
But there was no indication that the gas-field attackers wanted money, and no other demands or ultimatums were issued. In a statement sent to ANI, a Mauritanian news agency, they demanded the "immediate halt of the aggression against our own in Mali."
The statement, made by a group called Al Mulathameen, which has links to Al Qaeda in the Islamic Maghreb, the North African affiliate of Al Qaeda, claimed it was holding more than 40 "crusaders" — apparently a reference to non-Muslims — "including seven Americans, two French, two British as well as other citizens of various European nationalities."
Algeria's interior minister, Daho Ould Kablia, said, according to Reuters, that the raid was led by Mokhtar Belmokhtar, who fought Soviet forces in Afghanistan in the 1980s and recently set up his own group in the Sahara after falling out with other local Qaeda leaders.
Mr. Belmokhtar is known to French intelligence officials as "the Uncatchable" and to some locals as "Mister Marlboro" for his illicit cigarette-running business, the news agency said. His ties to Islamist extremists who seized towns across northern Mali last year are unclear.
The gas-field attack coincided with an escalation of the fight inside Mali, according to Western and Malian officials, as French ground troops, joined by soldiers of the Malian Army, engaged in combat with Islamist fighters. The officials said the French-Malian units had begun to beat back the Islamist militant advance southward from northern Mali, a move that had provoked the intervention ordered by President François Hollande of France.
The attackers seemed particularly incensed that Algeria's government had permitted the French to use Algerian airspace to fly warplanes and military equipment into Mali, according to their statement, which may explain why they chose Algeria for retaliation. Some Algerian military experts said the Algerian public also was unhappy about the government's decision.
"The setting in motion of a military machine in north Mali was going to have definite repercussions in Algeria," said Mohamed Chafik Mesbah, a former Algerian Army officer and political scientist, adding, . "There are going to be much worse consequences. There will be more attacks."
A senior Algerian official said the militants, who claimed to have come from Mali, had used three unmarked trucks to breach the gas-field compound, outside the town of In Amenas. An oil company official who had knowledge of the attack said the militants had shut down production at the site, an indication of carefully planning. But how and why they chose In Amenas, which is more than 700 miles from the Malian border and is much closer to Libya, were among the unknowns.
The facility is the fourth-largest gas development in Algeria, a major oil producer and OPEC member. The In Amenas gas compression plant is operated by BP of Britain, the Norwegian company Statoil and the Algerian national oil company Sonatrach.
Bard Glad Pedersen, a Statoil spokesman, said that of 17 Statoil employees who had been working in the field, four escaped to a nearby Algerian military camp, but he would not say how. The Sahara Media Agency of Mauritania, quoting what it described as a spokesman for the militants, said that they were holding five hostages in a production facility on the site and 36 others in a housing area, and that there were as many as 400 Algerian soldiers surrounding the operation. But that information could not be confirmed.
Islamist groups and bandits have long operated in the deserts of western and northern Africa, and a collection of Islamists have occupied the vast expanse of northern Mali since a government crisis in that country last March. Those groups, including Al Qaeda in the Islamic Maghreb, had pledged to strike against France's interests on the continent and abroad, as well as those of nations backing the French operations. In France, security has been reinforced at airports, train stations and other public spaces.
The militant groups are financed in large part through ransoms paid for the freeing of Western hostages, and regular kidnappings have occurred in the West African desert in recent years. At least seven French citizens are presently being held there, officials say.
Oil and gas are central to the Algerian economy, accounting for more than a third of the country's gross domestic product, over 95 percent of its export earnings and 60 percent of government financial receipts. Algeria is an important gas supplier to France, Spain, Turkey, Italy and Britain.
Algeria has also historically been known as a relatively secure place for foreign companies to work and invest. Sonatrach and the security forces had put tight security around oil and gas facilities during the struggle with Islamic militants in the 1990s, when energy infrastructure was never a major insurgent target.
Energy experts expressed concern that the Algerian raid could signal a new strategy by Islamic militants to attack the West by focusing on Western-operated oil and gas facilities in the region.
Helima Croft, a Barclays Capital senior geopolitical strategist,said if groups like Al Qaeda in the Islamic Maghreb "decide as a change in tactic they go after Western energy interests, then you have to look at a threat in all these countries, including Libya, Nigeria and Morocco."
She added: "This type of attack had to have advanced planning. It's not an easy target of opportunity."
Adam Nossiter reported from Bamako, and Scott Sayare from Paris. Reporting was contributed by Clifford Krauss from Houston, Rick Gladstone from New York, Elisabeth Bumiller from Rome, and Alan Cowell and Steven Erlanger from Paris.
© 2013 The New York Times Company Truthout has licensed this content. It may not be reproduced by any other source and is not covered by our Creative Commons license.