A man was arrested on suspicion of common assault after an egg was believed to have been thrown in the direction of Britain's King Charles during a walkabout on Tuesday.
The alleged assault took place while Charles, 74, who came to the throne in September after the death of his mother Queen Elizabeth, was visiting Luton, northwest of London.
A police spokesperson confirmed a man in his 20s had been arrested in Luton's St George’s Square and was in custody for questioning.
Last month, a man was detained by police after eggs were thrown at Charles and Camilla, his wife and the queen consort, as they carried out an engagement in northern England.
The latest incident comes as the royal family braces itself for the release of a Netflix documentary series on Thursday about the king's younger son Prince Harry and his wife Meghan, and their latest expected criticism of the royal household.
The US military said on Saturday it carried out multiple strikes in Syria targeting ISIS as part of an operation that Washington launched in December after an attack on American personnel.
Israeli fire killed at least three Palestinians in two separate incidents across Gaza, local health authorities said, as tension rises over continued violence.
Tens of thousands of people marched through Minneapolis on Saturday to decry the fatal shooting of a woman by a US immigration agent, part of more than 1,000 rallies planned nationwide over the weekend against the federal government's deportation drive.
At least one person has died in Australia's southeast where bushfires raging for days have razed buildings, cut power to thousands of homes and burned swathes of bushland, police said on Sunday.