Hillary Clinton 'distressed' by Northern Ireland tensions as two bombs found She spoke at a news conference in Stormont alongside Peter Robinson, the First Minister, who condemned the "despicable" threats and called on loyalists to cancel planned demonstrations. Martin McGuinness, the deputy First Minister, and former IRA commander, also met the US Secretary of State, who played an influential role in the peace process with her husband, former US presdient Bill Clinton. "I know Naomi Long and, obviously, I am very distressed by the news that she's been subjected to threats, that members of the Alliance party have had their homes and offices attacked," Mrs Clinton said. That's absolutely unacceptable and both Peter and Martin have spoken out in unmistakeable terms condemning this kind of intimidation, threatening behaviour. Feelings have been running high since Belfast Council voted to limit the number of days the Union flag can be shown, causing riots in some parts of the country. A loyalist mob set fire to offices of the centre-ground Alliance Party in Carrickfergus in County Antrim and the home of councillors in Bangor was attacked. The situation escalated as four men were arrested in Londonderry in connection with a viable bomb on Thursday night. Homes had to be evacuated as the army made the bomb - an improvised explosive device - safe. A letter bomb was found in a postbox in Clough, Co Down, and defused by the army. Stephen Martin, a Chief Superintendent, later said the explosively formed projectile (EFP) is similar to those used against the miliary in Iraq and Afghanistan. It could have ripped through an armoured patrol vehicle and killed police officers. "This is a weapon primarily designed to kill," he said. These EFP devices are used in places like Afghanistan and Iraq with deadly consequences. Ms Long, an Alliance Party MP, has been told to leave her home and not go to her office by the Police Service of Northern Ireland, who said there was a threat to her life. The former city councillor, who won the seat at the last general election from Mr Robinson, said: "This will not prevent me providing a constituency service to the people who elected me." Mrs Clinton has not let the renewed hostilities distract her from the visit and she is scheduled to visit the new Titanic Centre later today. She has been to Northern Ireland twice since becoming Secretary of State and held up the region as an example of somewhere that has overcome its troubles. It is one of Mrs Clinton's last foreign trips as Washington's most senior diplomat, before she steps down in the New Year. She was also a repeated visitor to the country with her husband, as he helped to work on the peace process. The couple turned on the Christmas lights in Belfast in 1995 a year after the first IRA ceasefire and three years before the Good Friday peace agreement. It will take place just five miles from the site of the Enniskillen bombing, which was one of the worst to hit Northern Ireland when it killed 12 people in 1987. The Queen visited Enniskillen earlier this year during her two-day Diamond Jubilee tour and a historic meeting with Mr McGuinness. Will Kerr, assistant chief constable of Police Service of Northern Ireland, warned: "To encourage thousands of people to come to Belfast city centre on one of the busiest days of the year would be madness." Mr Robinson also called on protesters to suspend their action.