Sinn Féin leader Gerry Adams has said those behind the unrest in east Belfast do not represent the people of the city.
Mr Adams said the Government and Tánaiste Eamon Gilmore, who is to visit the city this week, should show consistency in their approach to Northern Ireland.
He said he had invited Mr Gilmore to come to east Belfast to meet the communities there.
Last night, a bus driver was injured when rioting loyalists hijacked two buses amid further violent protests in Belfast over restrictions on flying the Union flag over Belfast City Hall.
Police were attacked with stones and bottles, while petrol bombs were thrown at houses and a church in the Catholic Short Strand district where people attending a meeting fled in terror.
The bus driver was believed to have been hurt by flying glass when a brick was thrown through his window in the lower Newtownards Road area.
He was taken to hospital for treatment for cuts to his face, the PSNI said.
Police used water cannon to help restore order, and one officer was injured.
A 17-year-old boy was arrested, and two men aged 70 and 26 were detained in a separate incident connected to disorder which followed a flag protest in the Great Victoria Street area.
Bus services in the east of the city were also suspended immediately after the hijackings and just before loyalists attacked houses and St Matthew's Catholic Church in the Short Strand.
Nobody was hurt, but neighbours claimed frightened people attending a meeting for people with special needs in an adjoining parochial hall had to run for cover.
A major conference of teachers planned for the city next November has been cancelled because of the continuing disorder.
Conall McDevitt, an SDLP member of the Northern Ireland Assembly and city councillor who voted for the flag to be lowered, said it was an unprovoked and unjustifiable attack on people's homes and a place of worship, and there could be no explanation for such depraved acts of violence.
He said: "This behaviour is as sickening now as it was when it first started - and more so, because the perpetrators know that they have no legitimacy and waning support.
"This is not a cause - this is simply the worst depths of human nature run amok."