LONDON: Families of troops killed when a Royal Air Force (RAF) plane crashed in Afghanistan demanded top-level resignations Thursday after a report accused the Ministry of Defence (MoD) of serious failures.

A study by lawyer Charles Haddon-Cave into the 2006 Nimrod spy plane explosion which killed 14 men identified a "failure of leadership, culture and priorities", Defence Secretary Bob Ainsworth told the House of Commons Wednesday.

"It's what we've said all along. The MoD tried to tell us everything was fine," Trish Knight, whose son Ben was killed in the crash, said.

"There should be some resignations by top people over the lies they have been telling us since 2006," she added.

Ainsworth also accepted the report's finding that "in our pursuit of financial savings, the MoD and the RAF allowed their focus on safety to suffer."

The 37-year-old Nimrod MR2 blew up over Kandahar in southern Afghanistan shortly after carrying out mid-air refuelling when leaking fuel spilled onto a hot air pipe.

The incident was the biggest single loss of life for British forces in more than a decade.

Ainsworth apologised to the families of those who died over the findings of the report, which singled out two now retired senior RAF figures for particular criticism.

"I am sorry for the mistakes that have been made and the lives that have been lost as a result of our failure," he said. "Nothing I can say or do will bring these men back."

In his report, Haddon-Cave said the MoD had suffered "deep organisational trauma" following a defence review in 1998 which saw budgeting prioritised over safety.

"There was a shift in culture and priorities in the MoD towards 'business' and financial targets, at the expense of functional values such as safety and airworthiness," he said.

He also criticised defence companies BAE Systems and QinetiQ over the plane's safety regime.

Ainsworth said he accepted the report's findings and would publish a detailed response before the end of the year.

The mother of one of the troops who died, Trish Knight, called for top brass to quit in the wake of the report's findings.

"There should be some resignations by top people over the lies they have been telling us since 2006," she said. "There should be resignations right from the very top."