Attack planned on royal yacht during Queen Elizabeth II's 1983 US visit: FBI

Queen Elizabeth II faced a potential murder threat during a 1983 visit to the United States, according to recently revealed FBI papers.Following the late Queen's death last year, the Federal Bureau of Investigation (FBI)revealed a stockpile of information connected to her visits to the United States.

They demonstrate how the FBI, which assisted in ensuring the monarch's safety throughout her travels, was concerned about IRA threats, as reported by the BBC.

An assassination threat was made against a San Francisco police officer.As perthe file, an officer who visited an Irish bar in San Francisco alerted federal authorities to a phone call from a man he met there.

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In the words of the officer, the maninformed him he was seeking vengeance for his daughter, who was "killed in Northern Ireland by a rubber bullet.

What was the threat?

The warning was issued on February 4, 1983, just a month before Queen Elizabeth II and her husband, Prince Philip, were scheduled to visit California.

"He was going to attempt to harm Queen Elizabeth and would do this either by dropping some object off the Golden Gate Bridge onto the Royal Yacht Britannia when it sails underneath, or would attempt to kill Queen Elizabeth when she visited Yosemite National Park," the document says.

In response to the threat, the Secret Service had planned to "close the walkways on the Golden Gate Bridge as the yacht nears". It is not clearwhat stepswere taken at Yosemite, but the visit went ahead. No details of arrests were published by the FBI.

Following a Freedom of Information Act request from US media outlets, the 102-page cache was published to the Vault, the FBI's information website, on Monday.

Many of the late Queen's official visits to the United States, notably the 1983 visit to the West Coast, took placeduring heightened tensions in Northern Ireland as a result of the Troubles.

The late Queen was in New York City for America's Bicentennial celebrations in 1976.

What do the records show?

The records show how a summons was issued to a pilot for flying a tiny plane above Battery Park with a placard that said "England, Get out of Ireland."

The papers indicate how the FBI stayed watchful to what it perceived to be the true threat to the late Queen.

Lord Mountbatten, her second cousin, was killedin a 1979 IRA explosion off the coast of County Sligo, Republic of Ireland.

An official FBI letter noted, "the possibility of threats against the British Monarchy is ever-present from the Irish Republican Army (IRA)" ahead of the late Queen's personal visit to Kentucky in 1989.

It went on to say that "Boston and New York are requested to remain alert for any threats against Queen Elizabeth II on the part of IRA members and immediately furnish same to Louisville," in Kentucky.

The late Queen, who owned racehorses, is said to have visited Kentucky numerous times throughout her lifetime to take in the state's equestrian events, including the Kentucky Derby.

The late Queen was set to attend a Baltimore Orioles baseball game with President George H Bush during a state visit in 1991.

The FBI notified the Secret Service that "Irish" agents were on the loose.

The bureau told NBC News that "additional records" may exist in addition to those disclosed this week, but no schedule for their release was provided.

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