Police were furious to find a "bomb" discovered at the French ambassador's residence in London had been planted by the French themselves to test British security arrangements, according to newly released government files. Source: Press Association
Two small containers of high explosives were discovered during a search of the residence grounds on the eve of a state visit by President Francois Mitterand(picutred with Margaret Thatcher) in October 1984.
The French security officer who planted them was subsequently found to have more explosives stashed away in his room at the Grosvenor House Hotel.
Ministers in Margaret Thatcher's government were aghast that the French were unwilling to offer any explanation - let alone apologise - for what had happened.
According to the Cabinet minutes, released by the National Archives, ministers said it was "inexplicable and unacceptable" before such an important diplomatic visit and demanded assurances there would be no recurrence.
"In particular assurances should be sought regarding security at Buckingham Palace," the minutes noted. "The police were naturally extremely annoyed at what had occurred."
US Airways plane makes emergency landing after bomb threat