Files relating to Queen Elizabeth’s visits to the United States in the 1980s and 1990s, which reveal threats made and a possible plot to kill her, have been released by the FBI.

Among the documents, posted on the FBI’s website, is a memo about Elizabeth and her husband Philip’s visit to the US West Coast in 1983.

According to information received by San Francisco police from Irish circles, a man who said his “daughter had been killed in Northern Ireland by a rubber bullet, then planned to harm Queen Elizabeth.”

He would achieve this either by “throwing an object from the Golden Gate Bridge onto the royal yacht Britannia as she passed under, or by attempting to kill the Queen during her visit to Yosemite National Park”.

Four years earlier, in 1979, the Irish Democratic Army (IRA) had assassinated Lord Louis Mountbatten, Queen Elizabeth’s cousin, in a bomb attack during the Troubles, the conflicts between republicans and unionists in Northern Ireland.

Another note, related to the Queen’s official visit 1991refers to threats from Irish organizations to disrupt events she was scheduled to attend, such as a baseball game and a reception at the White House.

Another document, of 1989states that even if no specific threats have been made against the Queen, “the possibility of threats from the IRA against the British monarchy remains present”.

There have been several attempts on the life of Queen Elizabeth, who died last September aged 96, mainly by the IRA.

In 1970, IRA supporters tried to derail the train she was traveling on west of Sydney, Australia, and in 1981, the IRA had planned a bomb attack during her visit to northern Scotland.