Rioting broke out across Belfast last night when hundreds of loyalists took to the streets to protest over the new flag policy at Belfast City Hall.
Two police officers were injured, one of them hospitalised, during clashes close to the city centre.
Trouble flared at Shaftesbury Square – a popular party spot near Queen’s University – after a man tried to drive a black van through a loyalist roadblock of about 200 people.
A spokeswoman for the Police Service of Northern Ireland said: “Police can confirm that a vehicle was driven erratically in the Shaftesbury Square area during minor disturbances.”
Eye witnesses said police officers were pelted with stones, bricks, bottles and other missiles.
Water cannon were deployed to the area but were not used against the rioters.
There were also reports of minor sporadic disorder in other parts of the city.
The fresh wave of violence broke out in spite of US secretary of state Hillary Clinton’s assertion that violence was no longer welcome in the region following the peace process.
Yesterday, more than 500 people attended a Worldwide Ireland Funds’ lunch in the £90 million Titanic visitor centre where Mrs Clinton was presented with a lifetime achievement award in recognition of her commitment to peace and reconciliation in Northern Ireland.
Mr Robinson and Deputy First Minister Martin McGuinness paid tribute to Mrs Clinton’s work in the North. They reminded her people there would always be grateful to her and she would always “get the warmest of welcomes”.