Some nine officers were injured and 18 people arrested in fresh violence overnight on the streets of Belfast, police said Saturday.
The Police Service of Northern Ireland (PSNI) used water cannon against a crowd of up to 300 people in the second consecutive night of violence by pro-British protesters.
The renewed wave of disorder follows several weeks of Protestant loyalist unrest sparked by the December 3 decision by Belfast City Council to limit the number of days it flies the British flag.
More than 30 petrol bombs, along with fireworks, ball bearings and masonry, were hurled at officers in east Belfast. None of the police injuries are life threatening, however one female officer required medical treatment at the scene.
Elsewhere, three attempted vehicle hijackings were made while a business premises was also broken into by several masked men, who stole a sum of money.
Northern Ireland’s First Minister Peter Robinson said Friday: “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.”
The December flag vote has raised tensions in the province, which endured three decades of sectarian violence until 1998 peace accords led to a power-sharing government between Protestants and Catholics.
Officers injured, 18 arrested in Belfast violence