London: Germany had planned to use chemical and biological attacks during a wartime invasion of Britain, newly-released documents have revealed.
Documents from the Ministry of Home Security and other bodies said that the aim would be to spread panic and start an evacuation that would block roads and prevent defending from forces reaching the coast.
Aircraft adapted to spray gas or foot-and-mouth disease, and even anthrax shells, were seen as possibilities, said the documents.
Intelligence also revealed that the Germans were planning to falsely accuse Britain of using gas in order to justify its own attacks, The BBC reports.
The Nazis were "rapidly preparing" by March 1941 and would not hesitate to attack, said the papers.
The documents detail the ominous movement of large amounts of chemicals from factories to "areas occupied by troops likely to take part in an invasion".
Intelligence chiefs were also mindful of a possible seaborne gas cloud threatening the country.
A document from August 1940 states that such an attack, using phosgene or chlorine, although "operationally difficult", could not be disregarded and could threaten an area up to 10 miles in width.
"Whenever an on-shore wind at night is forecast, a warning will be issued to all troops within five miles of the coast", reads the document.
The "warning zone" stretched from the east coast of Scotland all the way round the south coast of England to the Bristol Channel.
The secret memo alerted the public to a potential gas cloud "would be undesirable and should not be done".
The archives also reveal that experts expected an initial surprise bombardment of up to 2,500 airborne gas sorties, delivered by bomb or spray, during the first few days of a Nazi invasion.
Air superiority was considered vital for the Germans` amphibious assault on Britain.
Hitler eventually cancelled the invasion plans in January 1941.