Videos posted on the Belfast Nightwatch First Division Facebook page show the groups walking the streets at night.
In some of the videos there are angry confrontations with men who appear to be from minority ethnic backgrounds.
Standing outside what is confirmed as a HMO, a man who appears to be from the Nightwatch group advises that a ethnic minority man would be better staying home at night because he was “seen out on the street causing suspicious activity”.
“His best move,” the Nightwatch member said, was to “head home and stay off the streets at night” as there are teams patrolling “because there are that many undocumented men coming into this country”.
He challenges a white man in the doorway asking why he’s happy to “live with five undocumented men”.
The Nightwatch member then claims “undocumented men are coming into the country, raping our kids, raping our women, causing trouble on the streets”.
He gets aggressive claiming the man has no right to be on the street at night, and when asked to mind the noise, tells the man in the doorway, “be thankful it’s only noise,” adding, “take the message because next time it might not be as pleasant.”
Other videos show members of the Nightwatch group insisting that men leave the area and confronting a shop worker.
On the Facebook page the group describes itself as ‘Concerned Parents, from all communities, working together, patrolling Belfast streets, for the safety and protection of our children and vulnerable people’.
However, Green Party Councillor Brian Smyth said he has received “multiple complaints from people about a self-styled vigilante groups operating patrols in East Belfast and questioning people”.
Almost half of those arrested for race hate disorder in Belfast last August had previously been reported to the PSNI for domestic abuse.
Police data, obtained through a freedom of information (FOI) request by investigative website The Detail, highlights a significant overlap between public violent disorder and domestic violence.
Mr Smyth added: “Following on from the story showing half of those arrested for race riots were reported for domestic abuse, it’s important to know who these people are and have they got criminal records?
“I’m concerned about the aggression being displayed in these videos.
“I believe the police are looking into it. The police and the rule of law can’t be undermined, especially in a post-conflict society.”
The PSNI said it is “aware of a number of videos circulating on social media”.
Chief Inspector Dunne said: “The Police Service of Northern Ireland does not tolerate any type of vigilante activity and would caution any individual or group against taking the law into their own hands.
“It is the responsibility of the police service to enforce the law in Northern Ireland and we are committed to supporting the needs of all of our diverse communities.
“We will robustly review and deal with any offences reported to us.”