WASHINGTON - A trove of documents released this week by the FBI reveal details about an assassination threat against Queen Elizabeth II before a trip she and her husband made to the United States in 1983, as well as other security concerns linked to the Irish Republican Army.

The documents were published on the FBI’s website after a request under the Freedom of Information Act. The queen, who was Britain’s longest-reigning monarch, died in September 2022.

The plot to kill the queen was shared with a San Francisco Police Department officer in early February 1983, weeks before she and Prince Philip, the Duke of Edinburgh, were scheduled to visit the United States, the documents show. Specific names and other details are redacted from the report.

The unidentified officer said he had received a phone call on Feb. 4, 1983, from a man who claimed that his daughter had been killed in Northern Ireland by a rubber bullet. The officer frequented an Irish pub called the Dovre Club, which the FBI described as a gathering place for sympathisers of the IRA.

The 1983 visit, like some of the queen’s other trips to the United States, occurred during the 30-year sectarian conflict in Northern Ireland known as the troubles. About 3,600 people were killed during that period, when Britain deployed its military to the Protestant enclave to confront groups, including the IRA, that wanted to reunite Northern Ireland with the rest of Ireland.

The man on the phone call shared plans to harm the queen by either “dropping some object off the Golden Gate Bridge onto the royal yacht Britannia” when it sailed underneath or attempting to kill her during a visit to Yosemite National Park, the documents said. Specific details about how either plot would have been accomplished were not provided.

Officials noted that the Secret Service had intended to close the walkways on the Golden Gate Bridge when the yacht was nearby. Although it is unclear if any arrests were made, the documents note that the monarch’s visit was completed “without incident.”

The FBI did not immediately respond to a request for comment on Friday morning.

The New York Times covered the queen’s tour of the West Coast at the time, describing it as a sparkling affair punctuated by a visit to President Ronald Reagan’s ranch...