Production of postage stamps showing children taking part in physical activities has been halted over safety concerns, according to a report by a postal industry publication.

The President's Council on Fitness, Sports & Nutrition decided this drawing on one of the stamps showed a potentially unsafe activity. (USPS)

Linn's Stamp News says the U.S. Postal Service has pulled the series of stamps because the President's Council on Fitness, Sports & Nutrition has decided some of activities depicted for its "Just Move" campaign could be unsafe.

There are three offending drawings by artists Eli and Derry Noyes, out of 15 in the collection.

One shows a young swimmer doing a cannonball into water. In another, a child is skateboarding wearing a helmet but no kneepads. In the third, a youngster is doing a headstand without a helmet.

A New York Times parenting blog says it has confirmed with the U.S. Postal Service that the stamp series is on hold, saying the three drawings showed children moving in ways that "could prove detrimental to their health."

The physical activity stamp series was inspired by U.S. First Lady Michelle Obama to promote her anti-childhood obesity "Let's Move" campaign.