PSNI officers have arrested a 38-year-old man on suspicion of attempted murder after shots were fired at police today during protests over the removal of the British union flag from Belfast City Hall.

Police used water cannon against more than 100 protesters hurling fireworks, smoke bombs and bricks in the eastern part of the city shortly after a demonstration today outside City Hall calling for the flag to be reinstated on a permanent basis.

The violence, which stopped over Christmas, began again on Thursday and 19 police officers have been injured since then, bringing the total number of officers hurt since early December to more than 60.

Loyalists blamed today's fighting on Catholic nationalists who they said attacked them first.

Another night of loyalist street violence last night had left nine PSNI officers injured after they were attacked by large crowds across Belfast. A total of 18 people were arrested.

Tánaiste and Minister for Foreign Affairs Eamon Gilmore has condemned the latest attacks. “These attacks over the past three days are not the mark of legitimate protest but are the actions of a small group who want to bring Northern Ireland back to a darker past,” he said.

Mr Gilmore said the Government fully supports the efforts of and will remain in close contact with elected leaders in Northern Ireland to resolve the flags issue.

A police spokesman said officers in east Belfast had to deal with "serious public disorder" in the Castlereagh Street and Templemore Avenue areas last night when they came under sustained attack from crowds of up to 300 people. Missiles including fireworks, bricks and ball bearings were thrown. Police said over 30 petrol bombs were also thrown at officers.

It was reported that three attempted vehicle hijackings were made in the Beersbridge Road area, and that 14 arrests were made there. Water cannon was brought in but not used.

Police said three people were arrested when they cleared a protest in the Robbs Road area of Dundonald, close to the Ulster Hospital, at approximately 6pm last night.

Violence also broke out in the O’Neill Road area of Newtownabbey and lasted for several hours. Missiles including bottles and bricks were thrown for a time, resulting in one police officer being injured.

Police received reports of an attempted bus hijack in the area. A commercial premises on the O’Neill Road was broken into by several masked men who damaged the property and stole a sum of money. One person was arrested.

There have been violent protests in Belfast since early December when Alliance members on Belfast City Council voted with Sinn Féin and the SDLP to restrict the number of days on which the British union flag flies over City Hall to 15 from 365. A number of elected representatives have also received death threats, and Alliance Party offices have been burned by arsonists in Carrickfergus, Co Antrim.

Conall McDevitt, SDLP policing spokesman, said those organising the demonstrations on social media must be held fully responsible for the resultant violence.

“I appeal for calm today and over the weekend and ask people taking part in protests to reflect upon the violence, and [to] ask themselves if they want to be associated with that violence and [whether] that is the best way that they feel they can have their voice heard,” he added.

“Nobody is in doubt that some paramilitaries are exploiting these illegal protests to destabilise the situation and ultimately bring violence back on to our streets.”

Last night, Stormont First Minister Peter Robinson said violence against the police was a “disgrace” and claimed those behind the violence were playing into the hands of dissident republicans. Mr Robinson said: “The violence and destruction visited on the PSNI is a disgrace, criminally wrong and cannot be justified.

“Those responsible are doing a grave disservice to the cause they claim to espouse and are playing into the hands of those dissident groups who would seek to exploit every opportunity to further their terror aims.

“All right-thinking unionists will want to channel their energies into political activity and to support the cause of finding political solutions to the problems that we face,” Mr Robinson said.

“In Northern Ireland the ballot box has primacy and is the only vehicle for choosing the people’s representatives.”

On Thursday evening, 10 police officers had been injured and two protesters were arrested after rioting broke out. One of them, 23-year-old Christopher Shires, appeared in court yesterday. He was refused bail and remanded in custody.

Loyalist protesters, meanwhile, are planning to bring their union flag protest to Leinster House and ask for the Tricolour to be lowered next week.

An estimated 150 loyalists are expected to travel to the Dáil as part of a group organised by Willie Frazer, who was behind the Love Ulster parade in Dublin in 2006.

Additional reporting: Reuters/PA