Attack On Queen Elizabeth II? Man With Knife Arrested Outside Buckingham Palace

A man in possession of a knife was arrested outside Buckingham Palace on Wednesday, just seconds before Queen Elizabeth II passed by in a car from the area, British media reports said.

The arrest was made as the queen was driven from the palace for an engagement with the Duke of Edinburgh at St. Paul’s Cathedral for attending a service to mark the centenary of the Order of the British Empire.

A spokeswoman for the Metropolitan Police told U.K. media that the incident was not believed to be terror-related.

Read: Ariana Grande’s Fans Responds To Her Tweet About Manchester Bombing

“A man has been arrested in the Mall, SW1, in possession of a knife. Patrolling officers detained and arrested the man in the Mall at about 10.40am this morning," the spokeswoman said. “No one was injured in the incident and a knife was recovered. The man has been taken to a central London police station.”

The Met Police said late Tuesday that it has increased patrols and searches in the capital in the wake of the suicide bombing.

At least eight officers surrounded the man in the gardens next to St James's Park. The arrest came as U.K. Prime Minister Theresa May said a follow-up terror attack to the Manchester bombing could be "imminent."

However, concerns about the queen's safety erupted as the incident comes soon after the British police increased surveillance across U.K. following Monday nights terrorist attack at Manchester Arena in northern England. The Islamic State group was behind the attack, which claimed the lives of at least 22 people. Police identified 22-year-old Salman Abedi as the bomber who died at the scene of the attack.

On Tuesday, the queen held a moment of silence for the victims killed in the attack at Ariana Grande’s concert. The 91-year-old monarch stood at the top of the steps at Buckingham Palace with her husband Prince Philip, her son Prince Charles and his wife Camilla, before attending a garden party. The national anthem played during the moment to honor the victims.

"I know I speak for everyone in expressing my deepest sympathy to all who have been affected by this dreadful event and especially to the families and friends of those who have died or were injured," the queen said in a statement. "I want to thank all the members of the emergency services, who have responded with such professionalism and care."

The U.K. raised its national terror threat level from severe to critical Tuesday. MI5, the nation’s domestic security service, escalated the alert to the highest possible level following the bombings at Manchester Arena. A critical level alert means “an attack is expected imminently,” according to the security force’s guidelines.

The last time the terror threat in the U.K. was at a critical level was in June 2007 after an attempted car bombing at the Glasgow airport.