LEADING Scottish police say that the drafting of officers to Northern Ireland to cope with violence during the Ulster marching season should be a wake-up call to politicians over the pressure on frontline policing caused by cutbacks and a lack of manpower.

So far more than 30 officers have been injured in Northern Ireland and an MP hospitalised. Initially, some 600 police from mainland Britain, including almost 120 frontline officers from Scotland, were drafted in to help the cash-strapped Police Service of Northern Ireland (PSNI) at the traditional Twelfth of July marches which involve about 550 parades, of which 43 are classed as "sensitive".

However, following widespread clashes, another 400 officers were called over from across the UK yesterday. More than 1000 British officers are now providing support.

On Friday night, disorder flared in north Belfast as police attempted to enforce a decision banning a controversial Orange Order parade from passing the republican Ardoyne area on the Crumlin Road.

Disorder spread to east Belfast during six hours of violence, during which petrol bombs, bricks, fireworks, bottles, swords, heavy masonry and verbal abuse were hurled at police, of whom 32 were injured.

Democratic Unionist Party MP for north Belfast Nigel Dodds was taken to hospital after being struck by a brick during the unrest on the Woodvale Road in his constituency.

The violence has been condemned by Northern Ireland Chief Constable Matt Baggott, who said it was "shameful and disgraceful".

He added: "Much of the day across Northern Ireland passed peacefully.The parades in Derry/Londonderry and across many other areas were examples of tolerance and self respect but unfortunately the images shown across the world will be of violence and serious disorder.

"We were resolved to uphold the rule of law and the Parades Commission determination not to allow the parade past the Ardoyne. We did so impartially and firmly.

"I cannot praise highly enough the courage, professionalism and restraint of my PSNI colleagues, and those from England, Wales and Scotland who joined us in making sure the rule of law was upheld, at some personal cost."

The unrest has led to calls for police funding to be reviewed.

Chairman of the Scottish Police Federation (SPF) Brian Docherty said: "There are just under 120 officers from Scotland in Northern Ireland. That is about as much as we could spare because we still have to keep up resilience in this country.

"The violence should be a wake-up call to Westminster who should see this [spending cuts and violence at Belfast parades] as having gone too far."

Docherty said the SPF feared for the safety of Scots officers even though they have gone through training to learn how the PSNI operates.

He said: "The fear is that someone will be shot at or hit with a bomb.

"The situation is really, really tense. Thankfully we've not seen firearms, but this could change. It is a totally different policing environment over there."

PSNI assistant chief constable Will Kerr said there were 22 arrests across the country for public order offences and "more will follow".

He said: "Officers were viciously attacked by fireworks, masonry, ball bearings fired by catapults, laser pens, swords and other missiles.

"These attacks led to 32 police officers being injured.

"It would be wrong to say those injuries and the furious attacks on police lines were some sort of demonstration of righteous anger.

"It was nothing but thuggery on a grand scale."

PSNI budget cuts in Northern Ireland – the force has been ordered to make £135 million in savings by 2015 – have resulted in a large reduction in policing numbers.

About 6500 officers operate in the country today compared to 12,500 in 1998.

President of the Association of Scottish Police Superintendents, David O'Connor, said the policing problems stem from harsh Government cuts.

He said: "The UK Government has decided to reduce police officer numbers.

"The Government in Scotland has continued a commitment to keep officer numbers but it's not the case elsewhere.

"If they didn't have to get rid of officers, they wouldn't need to draft in officers from us."

He added: "This event in Northern Ireland happens every year. People know that it is going to happen. It needs to be planned for well in advance.

"We are fully supportive of the Police Scotland chief constable's decision to provide the mutual aid, but why do they need it?"

In 2015-16, central government revenue funding to the police will be reduced by £269 million, equivalent to a 4.9% real terms reduction.

A Home Office spokesman said the revenue funding to forces is prioritised and that police had the resources "to do their important work which includes providing mutual aid to other forces".

He added: "Police reform is working and crime is falling. Like all parts of the public sector, the police must play their part in helping to tackle the deficit."

Northern Ireland Secretary of State, Theresa Villiers, condemned the protests: "There can be no justification for this kind of behaviour., which does nothing to promote Britishness or the pro-union cause. Rather it undermines it in the eyes of most people in Northern Ireland and the rest of the UK.

"I pay tribute to the bravery of the PSNI and officers from Great Britain who did such an outstanding job in upholding the rule of law."

Police Scotland said they would not comment on the violence in Northern Ireland.

A spokeswoman said: "We can confirm that Police Scotland is providing mutual aid in support of the policing of the annual Orange parades in Northern Ireland following a request from PSNI."