Several people have been arrested, a police officer and a bus driver injured following a further evening of violence in east Belfast.
A bus was attacked on the lower Newtownards Road at around 7.30pm, the driver was taken to hospital with cuts to the face.
Peaceful protests in support of the Union flag at Belfast City Hall took place on the Crumlin Road at Hesketh, on the Donegall Road at Roden Street and in Dundonald.
Police said they came under attack from crowds throwing petrol bombs and stones as they responded to reports of petrol bombs being thrown from Pitt Park towards St Matthew’s Church in Bryson Street.
A spokesman said that water cannon was used due to the extent of the disorder.
“There was then an exchange of stones and other missiles between two factions until police restored order,” he said.
A 17 year old male youth has been arrested while one police officer is reported to have been injured.
Police have said they will remain at the scene with the objective of maintaining public safety.
Troubled flared just hours after the Chief Constable Matt Baggott and politicians on all sides appealed for calm. Business leaders also warned of the disastrous impact on trade.
A major conference of teachers planned for the city next November has been cancelled because of the continuing disorder - now in its seventh week - in protest at a decision to restrict the flying of the Union flag above City Hall.
A number of roads were blocked for a time. Some motorists held up in long tailbacks complained that police failed to take tougher action to clear masked demonstrators waving flags.
Bus services in the east of the city were also suspended immediately after the hijackings and just before loyalists attacked houses and St Matthews Catholic Church in the Short Strand. Nobody was hurt, but neighbours claimed frightened people attending a special needs meeting in an adjoining parochial hall had to run for cover.
Earlier on Monday two men aged 26 and 70 were arrested at a separate incident related to disorder following a street protest at Great Victoria Street earlier this evening.
Meanwhile a 16 year old male youth has been arrested in the Larne Road Link area of Ballymena following a protest in the area.
Protests have been taking place since the removal of the Union flag from Belfast City Hall on December.
Some of the protests have been followed by violence.
Unionist politicians have urged protesters to call of their demonstrations.