It has been reported Osama bin Laden's al-Qaeda terror network has been planning to make the biological poison ricin.
The London Timeshas claimed it found plans for nuclear devices in premises abandoned by al-Qaeda when the Taliban and its allies fled Kabul.
They reveal that instructions for making the poison were concealed amid a mass of scattered documents listing formulae for making explosives, fuses and detonation circuits.
They were at a gated house in Saraq Panza, Kabul, where two Arab doctors who worked there were beaten and killed as they tried to escape on Monday night.
One page of the instructions reads: "A certain amount, equal to a strong dose, will be able to kill an adult, and a dose equal to seven seeds will kill a child".
Another page says: "Gloves and face mask are essential for the preparation of ricin. Period of death varies from 3-5 days minimum, 4-14 days maximum".
Ricin, one of the most toxic biological agents, was found by UN weapons inspectors in Iraq as part of Saddam Hussein's arsenal of weapons in the 1990s.
The poison - which was used by Bulgarian secret police to kill the exile Georgi Markov as he walked across Waterloo Bridge, London, in 1978 - is produced from a toxic protein in castor oil seed.
PA