The four-year-old son of Prince William and Kate Middleton started last week at Thomas's Battersea, a private school in southwest London. The event was widely publicised in Britain and beyond.
London's Metropolitan Police said a 40-year-old woman was arrested on Wednesday in relation to an incident at the school on Tuesday, and was now in police custody. The woman is suspected of having gained access to the school, but police gave no details about exactly what had happened.
"We are working with the school, which is attended by His Royal Highness Prince George, to review its security arrangements after the incident," police said in a statement.
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