Aid worker's kidnappers set offbomb vest

The mission to save Linda Norgrove from her rebel captors was authorised by the Foreign Secretary William Hague while Prime Minister David Cameron was kept informed of the operation, officials said.

The Government defended the decision to launch the military assault, saying it was “right to try” to secure the release of Ms Norgrove, a 36-year-old aid worker from Scotland.

Her father John told The Sunday Times his family was devastated by the news.

General David Petraeus, the top Nato and US commander in Afghanistan, added that troops did “everything in their power” to save a woman colleagues described as an “inspiration”.

Originally from Sutherland in the Scottish Highlands, Ms Norgrove was seized by militants in Kunar province on September 26.

Three Afghan nationals also taken by the insurgents were later released, but Ms Norgrove continued to be held.

After a tip off revealed her whereabouts, US troops in the eastern province were sent in.

During the fighting seven insurgents were shot dead, it is believed. But Ms Norgrove was killed by her captors before she could be secured and led to safety.

According to reports, Ms Norgrove was either wearing the bomb vest or it had been held close to her before it was detonated by her captors.

Authorities in the US and the UK stressed that insurgent captors alone were responsible for the death.