FREDERICTON -- Police are warning parents after four young New Brunswick children voluntarily shared nude images of themselves online.

RCMP say the children, between the ages of eight and 12, shared nude pictures or videos on unspecified free websites in recent months.

The RCMP's Internet Child Exploitation Unit identified the children, who had not been asked for the images but simply shared them, said Sgt. Chantal Farrah.

"In these four cases, there were no offenders (asking for photos)," she said Wednesday.

All the children have been confirmed to be safe, she said, and police have spoken to their families.

The Mounties say such image-sharing is becoming more common, and are encouraging parents to be vigilant about what children are doing online.

"It is unfortunately becoming more common for young people, even children, to share exploitative photos and videos of themselves online, and once it's online it can't always be removed," Farrah said.

"Many young people also don't realize that publicly sharing images or videos of a sexual nature of a person under the age of 18 is a child pornography offence."

Farrah said in an interview children need to understand that they shouldn't do anything online that they wouldn't do at the mall.

The RCMP say parents and guardians should know what sites children are visiting, regularly monitor their devices, and talk to them about appropriate online behaviour.

They say they should also consider making a "family contract" that makes online rules clear.

"It is never too early to talk to your children," Farrah said. "You have to know what your kids are doing online."

Advice is available for parents at cybertip.ca, she said.