IN AMENAS, Algeria -- Here in the Sahara, it isn't the sandstorms, swarms of locusts and 125-degree summers that bother Norwegian Sigbjorn Ohnstad. It is the kidnapping threats he can't stand.
"They say they're targeting Scandinavians and Australians, because they always pay up," he says. "That's not good news for the Norwegians."
It is a difficult time for foreign oil executives such as Mr. Ohnstad of Norwegian energy company StatoilHydro ASA, who works at the huge In Amenas natural-gas field near the Libyan border. Local militants have threatened to kidnap or even kill them. In Amenas feels more like a military camp than a gas plant.
In light of the terror strikes in Algeria last week, the security may be justified. Two truck bombs in Algiers hit a United Nations office and the Constitutional Court, killing 37 people, 17 of them U.N. employees. It was the second such attack in eight months and bore alarming parallels with the bloodshed of the 1990s, when a civil war left close to 200,000 Algerians dead.
Al Qaeda in the Islamic Maghreb, or AQIM, which wants to drive foreigners out of Algeria, claimed responsibility for last week's attack. Its aim, according to a message on a Web site, was to "inflict harm on the crusaders and their agent, the slaves of America and France."
The violence is a problem for Western energy companies that have invested billions of dollars in Algeria. In May, AQIM, which had targeted mostly police stations and security forces, threatened Westerners working in the country. Many of the world's great oil provinces are dangerous places to work. Militant attacks on oil installations in Nigeria, coupled with the kidnapping of workers, prompted oil companies to close fields and withdraw staff last year, shutting a quarter of the country's production.
Terrorist targeting of Western oil-company staff, as in Algeria, remains rare. In December 2006, militants blew up a bus carrying expatriate oil workers in an Algiers suburb, killing the local driver and a Lebanese man. Then in March, a bus carrying gas-pipeline workers, some of them Russians and Ukrainians, was attacked about 75 miles west of Algiers. One Russian and three Algerians were killed.
The assaults have spooked a government heavily reliant on foreign investment to develop its hydrocarbon reserves. Already Europe's No. 3 natural-gas supplier behind Russia and Norway, with 18% of the market, Algeria plans to raise natural-gas and oil exports by more than a third over the next three years.
For the major oil companies, Algeria is a crucial province. BP PLC sees North Africa -- Algeria, Libya and Egypt -- as a "renewal" area, where much of the growth in its oil and natural-gas production will come from after 2015. It said last week's attacks won't affect its investment plans.
"Events like these may be part of life here for the foreseeable future," said Gerry Peereboom, BP's Algiers-based head of country. "We have to keep going."
After a 40-year hiatus, the British oil company returned to Algeria in the 1990s, when the country was in the grip of an Islamist insurgency. BP's operations, concentrated hundreds of miles south of Algiers and far from the violence, were largely unaffected. Still, there is concern the latest strikes could deter new investors as Algeria prepares to take bids for more exploration licenses in the natural-gas-rich south.
Companies such as BP and Total SA that have been here for years say they will stay put. Their security is already very tight. StatoilHydro's office, an elegant six-story building in the embassy district of Algiers, is surrounded by high walls topped with barbed wire. Temporary staff and visitors driving around the capital are accompanied everywhere by a driver and guard.
Security is an even higher priority at In Amenas. Soldiers from a nearby army base patrol the plant's perimeter nightly. All buses transporting staff to and from the local airport have a military convoy. Workers venturing offsite get their own armed escort, and vehicles are searched before entering.
The security regime is imposed not by the companies operating In Amenas -- StatoilHydro, BP and the Algerian state company Sonatrach -- but by the government, because of what an attack on foreign oil workers would do to its reputation. Oil executives said the biggest hazard so far isn't terror attacks, but carjackings by local bandits.
The In Amenas plant has a fleet of Toyota Landcruisers but can't use them at night.
At the plant, StatoilHydro and BP have worked to make life bearable for the 60 expat staff. There is a gym, an solar-powered indoor swimming pool and a soccer pitch. The Norwegians have waffle parties every Saturday -- a Nordic ritual -- and arrange volleyball tournaments. A social committee has been set up to create activities. But life can be frustrating. "It would have been nice to visit nearby towns," says Endre Hageberg, a StatoilHydro production engineer. "But we can't."