The U.S. Embassy in Algeria has urged American citizens in the oil-rich country to review their personal safety, after a terror attack on foreign oil workers killed one man and injured nine others.
On Sunday, a bomb exploded and gunmen fired at a bus carrying employees of an affiliate of Halliburton, an American corporation. Officials said a bus driver was killed. Several Britons and one American were wounded in the attack west of the capital, Algiers.
There has been no claim of responsibility.
In a statement, the U.S. Embassy said it is limiting the movements of its diplomats as it looks at the situation.
About 800 U.S. citizens live in Algeria. Sunday's attack was the first on foreigners in several years.
The employees work for Brown and Root - Condor, a joint venture between a Halliburton subsidiary and an Algerian firm.
A civil war in Algeria in the 1990s pitted Islamic militants against the military-backed government. Islamic militants began the conflict in 1992 after authorities canceled legislative elections being won by an Islamist party, the Islamic Salvation Front.
The conflict claimed the lives of some 150,000 people, but calm has largely returned to Algeria in the last few years.
Some information for this report was provided by AP and Reuters.