A PSNI spokeswoman confirmed that five officers were taken to hospital while others were treated at the scene of severe rioting, at the junction of Royal Avenue and North Street in the city centre, on Friday night.
An Ulster Unionist MLA is also understood to be among those injured and taken to hospital.
According to reports on social media pages belonging to east Belfast representative Michael Copeland, he and his family were involved in an incident with police and are said to be making allegations of heavy-handedness by officers.
Mr Copeland is believed to be making a formal complaint.
Meanwhile, a number of parked vehicles have been set on fire in the North Street area.
Police responded to the disorder with two water cannon and 20 baton rounds in a bid to restore calm.
A spokesperson said serious disorder also broke out in Carrick Hill, Peters Hill and Millfield in north Belfast.
Whilst facilitating the Parades Commission determination for tonight's parade and associated protests, police have come under heavy and sustained attack by crowds intent on creating disorder.
PSNI ACC George Hamilton
Commenting on the disorder, PSNI ACC George Hamilton said: "As Northern Ireland moves ahead, the effect of tonight's violence has the potential to damage the local economy and the reputation of Belfast as a tourist destination.
"As disturbances are continuing, I would call upon people of influence in communities and those in political leadership to do all possible to reduce tension."
Thousands of people took park in the Anti-Internment League rally, while six loyalist organisations held counter protests.
Two residents' groups - involving an estimated 300 people - were granted permission to demonstrate at Royal Avenue.
A further four protests were planned by other organisations, including No 2 District Loyal Orange Lodge, and aimed to attract a further 600 people.
They were given the go-ahead by the Parades Commission, but with restrictions on the numbers of supporters to be allowed.
What should have been a great week for the city, with thousands of visitors for the World Police & Fire Games, has ended badly and the image of Northern Ireland has been tarnished by violence.
Nelson McCausland, DUP MLA
The parade route started at Ardoyne Avenue, moving along the Oldpark Road, Rosapenna Street, the Cliftonville Road, through the New Lodge and into the city centre.
But as trouble flared police sealed off North Queen Street stopping the parade from progressing towards Royal Avenue.
Missiles were thrown from both sides at police lines. Water cannon was used at the bottom of the Shankill Road to keep the crowd apart from the rally, which then moved on towards west Belfast.
Reacting to the violence, North Belfast DUP MLA Nelson McCausland commented: "The march by a dissident republican rabble was designed to provoke a violent loyalist reaction and it succeeded.
"We would appeal for an end to any violence and want to meet urgently with the PSNI and the Secretary of State to discuss the events in Belfast tonight, including the role of the Parades Commission and the policing operation."
Sinn Féin's deputy First Minister Martin McGuinness tweeted: "Those responsible for tonight's violence against the police are the combined forces of the UVF & OO in N Belfast."
Organisers had previously appealed for calm.
Dee Fennell said: "This is a parade over a human rights issue, not a republican parade and certainly not a dissident republican parade."
Police have said all roads have re-opened to traffic, except the lower end of the Shankill Road, which remains closed.