This is a phenomena of mob violence which has been stoked up by individuals and social media.
PSNI Chief Constable Matt Baggott added it was fortunate nobody had been killed or seriously injured last night, and he praised police for doing a "magnificent" job.
More top news
There will be sunny spells for many but heavy showers will spread across the UK in the afternoon.
Children's Commissioner review found 28% of children in need of support were sent away because their illness was not deemed serious enough.
The former prime minister suggested a Jeremy Corbyn government would be a 'very dangerous experiment'.