Belfast's most senior police officer has blamed mainstream loyalist and republican paramilitaries for orchestrating sectarian violence in the east of the city.

Four people, including one policeman, were shot as gunmen opened fire during rioting in the Short Strand area on Monday.

At one point, the police were shot at and returned fire hitting a gunman, who was dragged away and has not yet been admitted to hospital.

Assistant chief constable for Belfast Alan McQuillan said: "On the loyalist side, we see clear evidence that the UDA and the UVF have been involved in this.

Alan McQuillan: Blamed paramilitaries for organising the violence

"Certainly in terms of the street disorder on the republican side we have seen large numbers of members of the IRA, many of them from outside the area, in the area.

"We believe that they are involved in organising the violence."

A high security force presence will be maintained in the area again on Tuesday and additional resources are also to be deployed.

Security forces were called to the interface area for the fourth night running as up to 1,000 people became involved in hand-to-hand fighting.

Nineteen police officers were injured. As they came under gunfire attack, one was shot in the lower leg.

Baton rounds

The latest trouble centred on the Lower Newtownards Road, where loyalists clashed with republicans living in the adjacent Short Strand.

Two Protestants were wounded by a republican gunman while a bus driver was injured by flying glass after his vehicle came under gun attack from loyalists in the area.

A spokesman for the Police Service of Northern Ireland said loyalists, in turn, had come under stone attacks while attending Jubilee parties in nearby Newtownards Road - adding to the tension in the area.

A total of 13 shots were fired at security forces.

Two people were arrested for public order offences.

Police discharged 61 baton rounds in an attempt to disperse rioters hurling petrol bombs, bricks and bottles at police and army lines.

We carry out a public service and our staff should be permitted to do that in safety without jeopardising their own position or that of passengers

Ciaran Rogan Translink

There had been a heavy police and Army presence in east Belfast throughout the day after three Protestants were injured in Cluan Place on Sunday night in a shooting incident.

Sectarian tensions boiled over between nationalists and loyalists after an uneasy day in the flashpoint area.

The bus driver injured in the disturbances suffered cuts to his face and neck, and was released from hospital on Monday.

Ciaran Rogan of Translink, the company that operates Northern Ireland's public transport, said he hoped bus services would not have to be withdrawn again, but stressed drivers must be protected

"We carry out a public service, we run buses and trains, and our staff should be permitted to do that in safety without jeopardising their own position or that of passengers," he said.

"We would appeal to the community for their full support at this very difficult time."