His comments come after Prime Minister Malcolm Turnbull accused Premier Daniel Andrews of failing to deal with gang violence in Melbourne.
Mr Turnbull said he was "very concerned at the growing gang violence and lawlessness in Victoria, in particular in Melbourne".
"This is a failure of the Andrews Labor government," he told reporters in Sydney on Monday.
Victoria's acting Roads and Road Safety Minister Philip Dalidakis hit back at the prime minister and said the state government would not be taking advice "from a bloke who can't even put on a life vest when he's on a boat in Sydney Harbour".
The prime minister was fined $250 in December for not wearing a life jacket while moving a dinghy near his harbourside home.
Mr Yoa said he wants authorities to acknowledge gang crime involving youths from African communities is a problem.
Senior Victoria Police figures have previously urged Victorians not to "play to the ego" of young people by calling them "gangs".
"I believe gangs do exist," Mr Yoa told 3AW radio.
"I was sort of in disbelief when I heard police say gangs don't exist."
Mr Yoa claimed he was attacked by a gang armed with machetes during a brawl after a Sudanese beauty pageant in Melbourne's west.
"We have issues within different communities, but (in) the Sudanese community the issue has escalated in the last two years," he said.
"And when you have Victoria Police coming in and ... try and cover up the issues ... it just goes around over and over again."
'See how we suffered'
Former South Sudan refugee and author Majok Tulba challenged the young people accused of wreaking havoc on the streets of Melbourne to spend a week in his home country.
"I have spoken to community leaders and I understand most of the young men are not child soldiers, they are not refugees, they are Australian born, and they regard what comes out of the mouths of their parents as history," Tulba told The Australian.
"Their parents talk to them about war, violence, gunfire, they think it was 100 years ago. I would like them to give up their lives in Australia for one week and experience South Sudan.
"See how we suffered and what we endured. What it means to be a refugee who is given a second chance. They will never take their lives in Australia for granted again."
Previously an African think-tank leader, Berhan Ahmed, told SBS News there was an issue with African youth crime and said the Victorian Police were dealing with the problem as best they could.
'We need to see correction rather than prison': Community leader
Dr Ahmed, who had worked the Victorian Police for nearly two decades, said the issue of crime had to be addressed and corrected, starting with the families.
"There are many reasons you can point at, but mainly school drop-out is one of the biggest crises facing these young people," Dr Ahmed, the CEO of the African-Australian Multicultural Employment and Youth Services, told SBS News.
"They are failing and then they are out at an early age. Also, employment is another issue adding to the problem. Most of these people are not employable by the majority of employers, so even some of the graduates are not finding the jobs as was expected in many of the communities.
"We need first (for) the families to be given some power to help (discipline) their kids. The community needs some sort of power to help young people to work with them. And also the government needs strategies – putting them in prison and taking them in and out is not helping us. The prison is becoming more training then punishment.
"So we need to see correction rather than prison."
EDITOR'S NOTE: This article was originally published as 'Stop political correctness': African community leader urges action on youth crime' the headline and story has since been amended after Mr Yoa admitted some of his story was untrue.
South Sudanese community leaders said Mr Yoa did not represent them.