“Before, they were in the marketplace smoking marijuana, drinking and stealing, but once the sport came, they started to change," Enoch Yapoi, the organiser, said.

He was not the only person to notice the huge number of teenagers in the area, many unemployed.

Papua New Guinea is in the middle of a population boom and it is creating what experts call a 'youth bulge' — when the number of young people exceeds all other age groups.

In recent years, studies have suggested that anywhere from 58 to 67 per cent of the country's population is under the age of 25.

The situation is more pronounced in highlands region, where in some areas it is estimated that 67 per cent of people are under the age of 18.

In comparison, Australians under 24 years old represented just 30 per cent of the population last year.

The average Australian is 37. The average Papua New Guinean is about 21.

Already, towns like Mount Hagen are struggling with a huge number of young people who don't have work or an education.

Local police commander Chief Inspector Jacob Kamiak is among those who are worried.

"It's a serious concern for me," he said.

"You can see on the streets, everywhere there are young people. We have a problem with alcohol and marijuana and all these things."

Police are concerned about things like illegal gambling, which they say is happening at the kickboxing event, but officers do not want to shut it down altogether.

"They started coming to training and they became responsible for themselves," said Mr Yapoi.

"It's a disciplined sport where one person will fight, so they learnt that they will have to take responsibility for themselves."

At the end of each battle, the fighters hug one another and then run a lap of the crowd, receiving high fives.

"We don't have good opportunities, but with kickboxing here, it gives us hope, we train hard and our goal is to become better men in the future," one of the young fighters said.

As Chief Inspector Kamiak drove through the town, he pointed out swelling new settlements that have formed on its outskirts, as more people leave their traditional villages and move to Mount Hagen.

He said there would "definitely" be an increase in crime if something was not done for the youth.

"They are completely neglected, those who have been neglected over the years, it's increasing," Chief Inspector Kamiak said.

Currently, the ratio of police to citizens in Mount Hagen is one to 1,700, because while the population has been growing dramatically, the number of police has stayed the same.

The force is also significantly under resourced.

Several police vehicles are off the roads because police headquarters has not paid mechanic bills.

The Chief Inspector wants to see more training and educational opportunities for young people, especially for those who have dropped out of school.

"They should be trained to do skilled jobs, to attend technical colleges, so they can at least make money to make their ends meet."

In the absence of a proper rubbish-collection program, waste has piled on street corners and rubbish flitters across roads.

With the Government so far failing to step in, Mount Hagen's youth are taking matters into their own hands.

As the sun rose over the city on a Sunday morning, around 200 people gathered to walk through the city streets and clean up the rubbish that littered the ground.

One of the organisers, Brian Tom, said the program was about helping those people who didn't have opportunities.

"Those youths who don't have a job, who are addicted to drugs and things, we are trying to train them up so that they realise their importance in the community," he said.

"We are trying our best to advocate for them and mentor them, so they become useful in our communities."

Mr Tom said he hoped it would reduce petty crime and harassment in Mount Hagen.

"Our passion and our commitment is we would like to see the community change, people change their mindset, their behaviour so we can live in a peaceful community," he said.

While the youth bulge is putting pressure on services, the people here believe it also represents an opportunity for PNG.

They want to see the next generation empowered to help shape the country's future.

Among the young people picking up the rubbish was Webster Kerro.

"I see that it has changed us, a lot of other youths as well, like we don't smoke drugs, drink beer or steal. It has changed me," he said.

Mr Kerro said he was now looking for work and he wanted to see more young people take part in the program.

"We need to change our mindsets and I want to call on the Government to look at what we are doing and support it," he said.

For Mr Tom, the simple program could change Papua New Guinea's future prospects.

"When they change their attitude, the community is going to change, the province is going to change and the country, automatically, will change," he said.