KANDAHAR (AFP) - The Taliban claimed Tuesday to have developed a new bomb nicknamed Omar after their fugitive leader and which they say is impossible Western mine sweepers to detect. The biggest killer of Western troops in Afghanistan are home-made bombs, known as improvised explosive devices or IEDs, which the Taliban deploy to wide effect in their eight-year insurgency and detonate by remote control. Western military intelligence officials have said most foreign troop deaths, which hit a record 520 last year, are caused by IEDs. But the Taliban claimed - ahead of a major assault by foreign troops on the southern Taliban stronghold of Helmand province - to have created a new IED using materials that make them undetectable. The networks spokesman, who identified himself as Yousuf Ahmadi, said the new bomb had been named after Taliban leader Mullah Mohammad Omar Mujahed. Omar is our latest weapon in the war against the invaders, he told AFP by telephone from an undisclosed location. Its a very effective bomb, it cant be detected by mine-sweeping vehicles and it causes more deaths, he said. He refused to provide more details, saying its our military secret but added that each Omar cost around 100 dollars to make.