London, Jan 31 (IANS): The Kensington Palace has asked social media firms for help in combating rising abuse aimed at British Duchesses Kate and Meghan, a media report said.

The royal household -- which oversees the offices of Prince William and Kate, and Prince Harry and Meghan -- has directly appealed to Instagram and Twitter for assistance in controlling vicious online comments aimed at both women, an informed source told CNN on Wednesday

The abuse is often made against one Duchess by supporters of the other.

"The volume of the comments, some of which are sexist and racist, is so significant that tackling them has been challenging" the source said.

"While the vast majority of comments were thoughtful and positive, it only takes a couple of people to turn the tone of the conversation to a very negative place."

Since its social media accounts were set up, the Kensington Palace has used both manual and automatic tools for monitoring them, and it deletes and reports anything deemed abusive, racist, sexist or violent.

These automated tools have helped bring down the levels of abuse, the source told CNN.

The source said that the Palace had previously contacted Twitter about particularly unpleasant or threatening comments, adding that Instagram had been especially helpful in providing monitoring tools to aid in blocking abusive comments.

A spokesperson for Twitter told CNN on Wednesday that the company did not comment on individual accounts, for "privacy and security reasons", adding: "Our abusive behaviour policy clearly states that we do not tolerate behaviour that harasses, threatens, or uses fear to silence the voices of others."

Instagram does not comment on individual accounts but does have a range of tools in place to counter bullying and offensive comments.