25/05/2017 12:38 AM AEST | Updated 25/05/2017 12:38 AM AEST

Have You Seen These Missing Children? Here's What They Could Look Like Now

The Australian Federal Police have issued a call for help.

Every year around 38,000 Australians are reported missing and while most of them are located within a short period of time, approximately 1,600 people -- many being young people under the age of 18 -- are still yet to be found.

As part of an attempt to combat these high numbers, the Australian Federal Police (AFP) released a series of six age-progressed images of missing and abducted children on Thursday for International Missing Children's Day in the hopes they may be recognised by someone in the community.

The images of Thomas Speath, Serena Speath, Leela McDougall, Mathieu-Pierre Etienne Macintosh, Bronte Watter and Isabella Watter, who all remain under the age of 18, were created by leading forensic artists from the United States National Center for Missing and Exploited Children and show what they could look like in 2017.

The six missing children left to right: [Top] Leela McDougall, Mathieu Macintosh, Bronte Watter. [Bottom] Serena Speath, Thomas Speath, Isabella Watter

AFP Assistant Commissioner Debbie Platz told HuffPost Australia International Missing Children's Day is "really incredibly important" for putting the focus on finding missing children, remembering children who have become the victims of crime and celebrating the young people who were able to return to their families.

"On average, we have 38,000 people who are notified to us as being missing each year. Of those, 20,000 are under the age of 18, so a high proportion of missing people are children," she said.

"Some of those are children who have run away, some have failed to tell their parents where they're going and there's a percentage that are stranger abductions, which is quite rare in Australia. The larger proportion of abductions are parental abductions.

"The important thing now is to focus on how we find people or find the missing children to reunite them with their families."

Platz said the six children that the AFP have focused on in the age-progressed images were picked because they're considered "long-term missing persons" who remain under the age of 18 and are understood to have disappeared while with a parent.

"I've actually met relatives of all of these children and I know, speaking to them, that they are extremely hopeful that this will bring about a renewed effort in trying to find the children," she said.

"It also provides an opportunity for people to see what they could look like today. The aged progressed images, we hope, will spark some inquiries that may help in finding them.

The AFP have called on the public to aid in the inquiries into any missing persons, saying any assistance is going to be "critical" in locating missing children.

"The most likely way of being able to find them [is] through somebody recognising them and providing that information," Platz said.

International Missing Children's Day, held on May 25 each year and established in the 1980s, came into effect following the disappearance of six-year-old Etan Patz from a New York street corner in 1979 and now acts as a commemoration of efforts around the world to locate missing young people.

Etan's story was the first to receive national coverage within the United States after his photographer father circulated his image, which featured on milk cartons, and influenced changes in the laws, methods and tactics of finding missing children.

Anyone with information that could assist in inquiries is urged to contact police via Crime Stoppers on 1800 333 000.