Paramilitaries blamed over riot
Loyalist paramilitaries have been blamed for rioting in north Belfast in which 40 police officers were injured.
Petrol bombs were thrown and a bus and 10 cars hijacked and set on fire in disturbances on the Crumlin Road.
The trouble followed the arrests of six men in connection with a loyalist feud, in which three men have been murdered.
Acting Assistant Chief Constable Wesley Wilson said he believed Thursday's riot was aimed at disrupting investigations into the feud between the LVF and UVF.
"I think this was an orchestrated attempt, because the police were in making arrests being pro-active - carrying out searches to try and stop this murderous feud that's ongoing," he said.
He said that while he did not have direct evidence he said that it was reasonable to expect that "loyalist paramilitaries such as the UVF" were behind the rioting.
Bombs
Petrol bombs and a blast bomb were thrown and a bus and 10 cars were hijacked and set on fire in the trouble, which broke out shortly before 1730 BST.
It is understood that none of the injuries sustained by police are life-threatening. Officers fired 11 plastic baton rounds during the trouble.
ACC Wilson said so many petrol bombs were thrown at police that they stopped counting.
He said that any allegations about police behaviour made about how police acted in the area would be investigated.
"I don't think there was heavy handedness," he said.
"The allegations that we have been made aware of are that in the face of provocation and unprovoked attacks on our officers while they're doing searches, eggs being thrown at them, one officer hit in the head with a brick, they say our officers were uncivil."
He said that no arrests were made at the time but that video evidence was being reviewed and he was confident police would identify rioters.
Complaints
He said that attempts by community representatives to calm thing down had not worked, but appealed for them to continue in their efforts.
Northern Ireland's criminal justice minister David Hanson condemned the violence.
"Once again it is loyalist paramilitaries who have brought violence into loyalist areas," he said.
DUP councillor William Humphrey said his party was concerned that some police officers from the force's Tactical Support Group had been "heavy handed".
"I am challenging how some officers behaved in this community yesterday and in the last weeks," he said.
Mr Humphrey said he had complained about what he saw in a detailed meeting with the police on Thursday and would be seeking a further meeting with senior officers.
The area's SDLP assembly member, Alban Maginness, said there was no excuse for the riots or the viciousness of the hostility and violence directed at the police.
"We cannot have a situation where loyalist criminals organise and begin a riot just because the police move to hold them to account under the law," he said.
Meanwhile, the funeral of the latest victim of the loyalist feud has taken place in north Belfast.
Stephen Paul, 28, was shot dead as he sat in a car in Wheatfield Crescent last Saturday night.