LONDON (Reuters) - Afghan gunmen killed a British woman during a failed rescue bid by US troops which was launched because her life was considered to be in grave danger, Britains foreign minister said on Saturday. Several insurgents were killed in Fridays attempt to free Linda Norgrove, 36, after she and three Afghan colleagues were abducted last month in rugged eastern Kunar province, a lawless area bordering Pakistan where insurgent activity is high. It is with deep sadness that I must confirm that Linda Norgrove, the British aid worker ... was killed at the hands of her captors in the course of a rescue attempt last night, Foreign Secretary William Hague said in a statement. A Foreign Office source said US forces conducted the rescue attempt and that no British troops were involved. Media said that American special forces had mounted the operation. Norgrove was abducted on September 26 but there had been a media blackout in order not to raise the value of the worker in the eyes of her captors. Referring to the raid to rescue Norgrove, Hague said that Britain worked with allies to act on information that her life was in danger, but the Foreign Office declined to elaborate. Responsibility for this tragic outcome rests squarely with the hostage takers, Hague said, adding: From the moment they took her, her life was under grave threat. Given who held her, and the danger she was in, we judged that Lindas best chance lay in attempting to rescue her. It was unclear whether the Taliban were behind the kidnapping. This year has been the most violent in the nine-year NATO-led campaign against Taliban insurgents in Afghanistan, and in August gunmen killed eight foreign medical workers, including British surgeon Karen Woo. Born in Sutherland in northern Scotland, Norgrove was regional director of a USAID project designed to create jobs and strengthen the economy in unstable areas, a plan seen as key to robbing the Taliban of support among the Afghan population. She spoke Dari, an Afghan version of Persian. Pressure has grown in the United States and Britain to withdraw troops from Afghanistan amid a flood of media reports on rising troop casualties and the killing of aid workers. An earlier rescue mission of a foreign hostage proved controversial - a raid to free Briton and New York Times reporter Stephen Farrell last year provoked anger after his Afghan colleague and a British soldier were killed.