LONDON - Northern Ireland's First Minister Peter Robinson on Sunday called for peace as riots erupted in Belfast for the third night running, injuring a police officer.
Seven officers were injured on Saturday after being attacked with petrol bombs by Protestant rioters in the Northern Irish capital, a spokeswoman said.
"It's very important that this violence stops," said Mr Robinson.
"It's very important that cool heads prevail in these circumstances and I hope people will obey the announcement and statement by the Orange Institution that people should desist from violence.
"The only kind of protest that is ever justifiable is a lawful and peaceful protest," he added.
The Police Service of Northern Ireland (PSNI) said one officer had been injured in Sunday's clashes.
Bricks, bottles, furniture and other missiles were hurled on Saturday night by hooded youths, some with British flags covering their faces.
The seven officers injured on Saturday did not require hospital treatment and remained on duty.