Police in Northern Ireland have 'appealed for calm' as they respond to incidents across Belfast and other areas.
It comes as Eleventh Night is marked in the North - a night which traditionally sees large bonfires lit in many loyalist areas.
Police have reported outbreaks of trouble throughout the night.
In one case, a bus in Newtownards, County Down was lit on fire after it was hijacked by a "number of masked men".
Police are currently in attendance after a bus was set on fire in the Westwinds Estate this evening. At around 7.30pm it was reported that a number of masked men, one carrying a suspected firearm, hijacked the bus in Blenheim Drive before setting it on fire.
— PSNI (@PoliceServiceNI) July 11, 2018
Elsewhere, police discovered the remnants of "what is believed to be viable pipe bomb type device" after a loud bang was heard in east Belfast.
In a statement, PSNI Assistant Chief Constable Alan Todd said: “Police have received information from the community which indicates that the East Belfast UVF intend to orchestrate and participate in serious disorder in East Belfast this evening directed against my officers.
“I would strongly urge people to desist from engaging in any violent or criminal behaviour. I would also appeal to those who have influence in this community to discourage people from taking part in any illegal activity."
Police operations were earlier launched to reduce the size of some of the bonfires, with officers working to protect contractors brought in to remove material.
Apologies in advance for the noise tonight if we are called to your area - be assured we’ll be working hard with our colleagues #keepingPeopleSafe and won’t be there just for the craic! Whether going out or having a quiet night in always be considerate of others in your actions pic.twitter.com/zLstUlWcFH
— PSNI Air Support (@PSNIAirSupport) July 11, 2018
