BRICK TOWNSHIP, N.J. (CBS Philly/CBS Local) School officials in New Jersey are warning parents of a disturbing social media challenge that encourages children to commit dangerous acts, including physical harm and suicide.

The so-called “game” known as the “Momo Challenge” has been circulating for months. It uses a creepy-looking avatar to communicate with children via the smartphone messaging application WhatsApp or through Facebook. Police say children are encouraged to contact Momo, and then asked to post photos or video of them committing violent acts. The avatar blackmails children by telling them that she has damaging information and will release it if they don’t play the game.

The Brick Township Public Schools in New Jersey asked parents to monitor their children’s use of social media and the internet after a local parent reported that an elementary school student shared descriptions of the challenge with first-grade classmates, and allegedly had acted on some of Momo’s directions.

According to a Washington Post report this fall, at least three deaths have been investigated in connection with the challenge in other countries.

The challenge has prompted police departments worldwide to also issue warnings.

According to cyber experts, the challenge is nothing but a hoax that aims at stealing personal data and torturing children physically and mentally.

Some police departments have also reported “Momo” copycats.

Police say children should never respond to unidentified messages on social media and parents should advise their children to never share personal data, photographs or phone numbers on the internet.