LONDON (AFP) - The most senior British soldier to die in Afghanistan warned that a helicopter shortage was putting troops at risk from roadside bombs shortly before he was killed by one, a report said Saturday. Lieutenant Colonel Rupert Thorneloe, commanding officer of the 1st Battalion Welsh Guards, died in July when his convoy hit an improvised explosive device (IED) near Lashkar Gar in southern Afghanistan. The previous month, he submitted a weekly report to the Ministry of Defence in London warning that helicopter shortages were increasing the danger from IEDs, the Daily Mail reported. I have tried to avoid griping about helicopters we all know we dont have enough, Thorneloe wrote in the leaked email. We cannot not move people so this month we have conducted a great deal of administrative movement by road. This increases the IED threat and our exposure to it. Thorneloe, who added that the current helicopter levels were unsustainable, was in charge of more than 1,000 troops. According to the report, Thorneloe addressed the issue in a confidential weekly update to commanders in London dated June 5. The newspaper said it had not printed the precise details of his complaints because their publication might endanger the lives of British troops in Afghanistan. Browns critics argued that a shortage has forced British soldiers to use roads where they regularly become targets for bombs set by insurgents. The newspaper said the documents were leaked by a defence ministry official to opposition Conservative lawmaker Adam Holloway, a former army officer. Defence Secretary Bob Ainsworth said the government was committed to providing more helicopters for the military. We know the value of helicopters on operations and that commanders could do with more, he said in a statement. That is why we are increasing the numbers and types, improved engines and almost doubled flying hours.