US Secretary of State Hillary Clinton has condemned the recent surge in sectarian violence in Northern Ireland, calling for differences to be overcome by 'peaceful and democratic' means.
'The remnants of the past need to be quickly, unequivocally condemned. The only path forward is a peaceful and democratic one. Violence is never an acceptable response to disagreements,' Clinton said at a news conference in Belfast on Friday.
Clinton arrived in the Northern Ireland capital from Dublin, in the Irish Republic, where she attended an international conference.
Her eighth visit to the once troubled British province of Northern Ireland was described as her 'farewell' by local politicians.
Clinton has said she will step down as Secretary of State when US President Barack Obama begins his second term in January.
She had earlier met with Peter Robinson, the Protestant First Minister (regional government leader) of Northern Ireland, and his deputy, Martin McGuinness, from Sinn Fein, the pro-Irish nationalist party.
Earlier in the day, police said four men had been arrested in Londonderry, the province's second city, following the discovery of a 'viable explosive device' that had been made safe.
Police did not link the find with Clinton's visit. A letter bomb was later discovered inside a postbox in a village in County Down, south of Belfast.
Clinton said she joined both leaders in condemning the recent violence that erupted between Protestants and Catholics after the Belfast city council decided to fly the Union Jack above City Hall on certain days only - rather than all year round.
With more protests expected in the city, Clinton urged: 'People have strong feelings, but you must not use violence as a means of expressing those strong feelings.'
The flag, signifying Northern Ireland's links with Britain, has been flying on top of the building since 1906. After the Irish War of Independence in 1922, the six provinces of Northern Ireland remained with Britain, while the former southern Ireland became an independent state - now the Republic of Ireland.
Monday's decision by the council prompted angry protests from Loyalists - supporters of the pro-British Protestants in the province - who stormed the building. Daily protests and clashes with Catholics followed.
They took an unpleasant turn when Protestants directly targeted the homes and offices of members of the small, cross-confessional Alliance Party, whose votes secured the passage of the flag rules initiated by Catholics on the city council.
Clinton recalled she first came to Belfast in 1995, to switch on the Christmas lights outside City Hall with her husband Bill, then president of the United States.
She praised the remarkable progress made towards peace and reconciliation in the province since then. Peace required sacrifices, compromise and vigilance, she said, and the events of the past week showed the 'work is not complete'.