The US embassy in Algiers is warning potential targets about an Al Qaeda threat to launch missile attacks against planes chartered by foreign oil firms in North Africa, officials said on  Friday. The warning comes after US officials expressed concern about the fate of thousands of shoulder-launched missiles in neighbouring Libya, where Muammar Qadhafi was overthrown last month by a rebel movement. "The US embassy in Algiers received threat information," the State Department said when asked about a newspaper report that Al Qaeda in the Islamic Maghreb (AQIM) planned missile attacks against planes with oil workers. "We continue to face a significant terrorist threat from Al Qaeda, its affiliates and its adherents." Both the embassy and the State Department's Overseas Security Advisory Council then "acted quickly to alert potential targets to the threat," it said. Mark Toner, a State Department spokesman, later said it was his "understanding" that the threat involved Al Qaeda missile attacks against planes chartered by foreign oil firms. The Algerian newspaper Al Khabar said US embassies in the Sahel and North Africa region received an electronic message from US security services that Aqim was preparing to carry out such attacks. The newspaper referred to information proving that Aqim possessed a "large number" of Sam 5 and Sam 7 missiles it planned to use to attack planes carrying staff from foreign firms, "particularly British and American." The State Department did not say that such firms were targeted, but indicated that the United States continues to work "very closely with our key partners on the threat from international terrorism, including the role that Al Qaeda continues to play." "Information is routinely shared between the US and our partners in order to disrupt terrorist plotting, identify and take action against potential operatives, and strengthen our defenses against potential threats," it added. "The government of Algeria has long been one of our strongest partners in this fight." The European Union's counterterrorism co-ordinator, Gilles de Kerchove announced on Sept.5 that Aqim had acquired weapons stockpiles in Libya, including surface-to-air missiles capable of shooting down planes.