Twelve RUC officers were injured, one with serious head injuries, in a disturbance in Ballymena, Co Antrim, early yesterday.
An RUC spokeswoman said the incident began after officers tried to disperse a small group of Celtic football supporters in the street. The men attempted to erect a Tricolour and when the officers tried to stop them, a crowd gathered and began to throw glasses and bottles.
"The situation rapidly deteriorated into a serious disturbance resulting in 12 officers being injured. Two were hospitalised, one with his leg broken in three places and another with serious head injuries," the spokeswoman said. Six people were arrested for offences, including assault and public disorder.
Meanwhile, two children, aged 18 months and four years, and their babysitter escaped injury when a pipe-bomb exploded outside a house near Armagh city yesterday morning.
No one was injured after eight shots were fired at a house in Lurgan, Co Armagh, shortly after 6 a.m. yesterday.
Sunday morning also saw two arson attacks. Two women and a man escaped by a bedroom window from a house in Omagh, Co Tyrone. The front door and hall were damaged in a fire.
In Dunmurry, on the outskirts of Belfast, a window in a house at Areema Drive was removed and liquid poured inside and set alight. No one was injured in the fire which badly damaged the house.