PSNI are investigating YouTube footage after shots were fired during the show of strength in Ardoyne and young people under 10 were pictured wearing paramilitary-style clothing.
On Friday Children's Commissioner Patricia Lewsley-Mooney revealed she had spoken to police about the images of children marching in the parade.
"This specific incident caused me concern that children are being put in this vulnerable position," she said.
"But I think what we need to look at is the broader issue of how irresponsible adults are putting children across NI into vulnerable situations and very often at risk, with regards to their own safety."
Mrs Lewsley-Mooney said she has also discussed her child safety concerns with Social Services, adding that parents should be held account.
It came after a meeting with DUP politicians who have expressed their outrage at the incident.
Nigel Dodds, MP, said: "We are all appalled at the images we saw on our television screens with shots being fired as these young children stand by dressed in these paramilitary uniforms.
"We will certainly be pursuing this matter very, very strongly."
Mr Dodds said parents "need to be brought to book" over their actions in permitting children to take part in the parade.
He added that the incident was completely different from children taking part in Union flag protests.
"I think there's a particular outrage about those who are being used to glorify terrorism and paramilitarism.
He said: "That's in a different category altogether."