Reuters

Loyalists clash with police officers outside the City Hall in Belfast following a vote by local councilors to stop flying the British flag every day.

Fifteen police officers were injured when hundreds of people tried to storm Belfast City Hall in Northern Ireland over a plan to stop flying the British flag as it currently does every day of the year, ITV News reported.

The violence broke out after Irish nationalist councilors from the Sinn Fein and SDLP parties voted to take down the flag which has flown above the city hall every day since the building was opened in 1906.

The decision means the flag will be flown only for 17 days of the year, as is the case at the provincial assembly at Stormont.

Nationalist and Unionist parties share power under a 1998 peace deal that largely ended 30 years of sectarian violence in which more than 3,600 people died.

Read more on this story from ITV News

Many of the protesters who clashed with police were carrying British Union flags.

Reuters reported that the attempt to storm the building was repelled by police.

A photographer from the Press Association news agency and two security guards were also injured, a police spokeswoman told Reuters.

Peter Morrison / AP

Police and protesters face off during clashes that saw 15 officers and three others injured.

Dozens of police hurt in Northern Ireland sectarian clashes

Democratic Unionist Party councilor Ruth Patterson described the vote to remove the flag as "divisive, destructive and disrespectful of anything remotely Protestant, anything remotely British," ITV News reported.

Northern Ireland's First Minister Peter Robinson condemned the violence.

"There is no excuse or justification for attacks on police officers, council staff, and property," he said, according to ITV News.

"Such behavior is not representative of those who campaigned to maintain the Union flag flying over Belfast City Hall," he added. "Those who talk most about building community relations have by their actions in the council substantially damaged relations across the city."

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Nationalist parties, which aspire to break from the U.K. and join a united Ireland, last year for the first time secured more seats on the council than Unionist parties, which support maintaining Northern Ireland's position in the United Kingdom.

Gerry Kelly, a member of the Northern Irish Assembly, strongly criticized the police, according to ITV News.

"I have to say, and I don't use these words unless I really mean them, it was a disgraceful police operation -- or lack of a police operation," he said. "If that had been 1,000 or more republicans, it would have been very different."

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"They indiscriminately attacked cars. We are very, very lucky that they didn't get into the building or we could have been dealing with a lot more injuries," he added. "I am angry because it's not as if they were taken by surprise. This was a well-planned protest."

ITV News, a U.K. partner of NBC News, and Reuters contributed to this report.

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Agencja Gazeta / Reuters

Members of Poland's Internal Security Agency (AWB) and the Prosecutors Office sit in front of a screen showing evidence of a planned attack, during a news conference in Warsaw, Tuesday.

Polish officials said Tuesday they had arrested a radical nationalist who planned to detonate a vehicle loaded with 4.4 tons of explosives outside parliament, possibly when the president and prime minister were in the building. 

Prosecutors said the man, a scientist who works for a university in the southern city of Krakow, had assembled a small arsenal of explosive material, guns and remote-controlled detonators and was trying to recruit others to help him. 

A video recording taken from the suspect showed what prosecutors said was a test explosion he conducted, leaving a large crater in the ground. 

'Anti-Semitic,' 'xenophobic' motives
Polish television, citing sources close to the investigation, said the suspect planned to copy methods used by Anders Behring Breivik, who killed 77 people in bomb and gun attacks in Norway last year and said he was driven by far-right views. 

"The suspect does not belong to a political group or party. He claims that he was acting on nationalistic, anti-Semitic and xenophobic motives," prosecutor Piotr Krason told a news conference. 

"He carried out reconnaissance in the neighborhood of the Sejm (parliament). This building was to be the target of the attack. He collected explosives and materials for detonation," Krason said. 

Reuters

A combination of handout photos distributed by Poland's Prosecutors Office Tuesday, showing evidence recovered by police of a planned attack in Warsaw.

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Poland has no experience of militant violence in its modern history. Society is though deeply polarized between supporters of liberal values and those who believe the country is neglecting its Catholic roots and succumbing to foreign influence. 

Agencja Gazeta / Reuters, file

File photo of the chamber of Parliament during the first session of the Polish Parliament in Warsaw November 8, 2011.

Earlier this month, a rally in Warsaw by right-wing nationalists turned violent, when youths in the crowd started throwing flares and stones at police. 

Earlier Tuesday, prosecutors said they had initiated legal proceedings against the bomb plot suspect on Nov. 5 and that Poland's Internal Security Agency would handle the case. 

"The case looks very serious," Pawel Gras, a government spokesman, told TOK FM radio station. "We know that the possible targets were to be the president, the parliament and the government."

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