The PSNI's Chief Constable has said praised the "remarkable" officers who policed the violent disturbances in north Belfast earlier this week.
Speaking after this afternoon's meeting of the policing board in Belfast, Matt Baggott said their courage had been "outstanding".
The chief constable said many of those injured had returned to their normal policing duties the next day, such as dealing with road accidents and domestic violence.
"We expect them to stand on the front line one minute and then the next day, keep our communities safe".
He said "no matter how people feel" there can never be an excuse for the violence witnessed in the Carlisle Circus area this week.
He said "keeping the peace" there had come at a "considerable cost" and this was "unacceptable".
Mr Baggott said work needed to be done on removing the reasons why people riot.
"Many of those rioting the other night... it was just an excuse. It was alcohol related, it was the mob rule, it was local anarchy. Many, many people living in those communities were put in fear by others in that community".
He said it was now up to "all those in positions of leadership" to work towards finding a resolution and to have local agreements in place before a large loyal order march takes place at the end of this month.
He added that when you have a situation where rioting is orchestrated on the first night, it continues for the further nights. "There is no such thing as a one night riot".
Earlier the organisers of a Belfast parade, during which bands played controversial music outside a Catholic church, apologised for any offence caused to the clergy and parishioners.
Fr Michael Sheehan, the administrator of St Patrick's Church on Donegall Street, described the apology by the Royal Black Institution as a positive development.
Tension over the incident was a factor in the recent rioting.
The Parades Commission had restricted bands passing the church to playing a single beat, but the order was defied, and The Famine Song was played.
The song has featured on the terraces during football matches in Scotland between Celtic and Rangers.
It includes the line: "The famine is over, why don't you go home?"
Despite the Royal Black Institution's unprecedented apology, its anger towards the Parade Commission remains.
A major rally is due in Belfast on 29 September to celebrate the centenary of the signing of the Ulster Covenant.
A march past St Patrick's is part of the planned route.
