Smartwatches designed to help parents keep tabs on children could create privacy and security risks, activist and consumer groups said Wednesday as they called for probes by regulators.

A coalition of child protection, consumer, and privacy groups asked the US Federal Trade Commission to investigate the risks posed to children by the devices and also called on retailers to stop selling the watches.

The groups said consumer organizations in Europe were expected to file similar complaints with EU regulators.

The organizations contend that the devices, instead of keeping children safe, could make them vulnerable to hackers or criminals.

"By preying upon parents' desire to keep children safe... these smartwatches are actually putting kids in danger," said Josh Golin of the Campaign for a Commercial-Free Childhood in a statement.

"Once again, we see Internet of Things products for kids being rushed to market with no regard for how they will protect children’s sensitive information. Parents should avoid these watches and all internet-connected devices designed for kids."

The actions come after research by the Norwegian Consumer Council highlighted security flaws in smartwatches designed for children, which transmit and store data without encryption.

With two of the watches, an attacker was able take control of the watch, eavesdrop on conversations, communicate with the child, and access stored data about the child's location. 

The Norwegian group also found that a "geofencing" feature meant to notify parents when a child leaves a specified area did not work as advertised, according to the organizations.

The study examined smartwatches sold under the Caref brand, marketed as Gator in Europe, SeTracker, Xplora and Tinitell.

"The devices implicate not only the data privacy of children, but also their personal safety," said a letter to the FTC by the Electronic Privacy Information Center, Center for Digital Democracy, Campaign for a Commercial-Free Childhood, Consumer Federation of America, Consumers Union, Public Citizen and the US Public Interest Research Group.

"The devices create a new vulnerability that allows a third party to find a young child at precisely the time when the child is separated from a parent or guardian."

The same coalition warned last year of similar risks from internet-connected dolls, prompting an FBI warning and leading to many retailers taking the products off their shelves.