LONDON (AP) — Britain's royal family is warning that it will block trolls posting offensive messages on its social media channels — and may report offenders to the police.

Buckingham Palace, Clarence House and Kensington Palace issued new guidelines on Monday, spelling out the policy banning offensive, hateful and racist language.

The guidelines come amid concern about the online abuse aimed at the wives of Prince William and Prince Harry. Much of the social media abuse has centered around rival fans of the Duchess of Cambridge and the Duchess of Sussex.

The royals say guidelines were introduced to try to maintain a safe environment on their social media channels and calls for users to show "courtesy, kindness and respect."

The Royal Family site on Twitter has some 3.87 million followers.