Former American senator Gary Hart, a personal representative to US secretary of state John Kerry, has said he is "personally dismayed" at the recent acts of violence in Northern Ireland.

Commenting for the first time on this week’s attacks on Sinn Féin representatives and the killing of former senior IRA member Gerard ‘Jock’ Davison, Mr Kerry’s representative assigned to monitor events in Northern Ireland said he and fellow US diplomats were “very carefully” following the events.

Speaking from Colorado, the former US presidential hopeful told The Irish Times they were observing events particularly to see whether a pattern of violence was forming.

“These are not good signs and they further complicate the effort to stabilise the devolved government in Northern Ireland and to move that government forward. It just makes the complex economic and political issues that much more complicated,” he said.

Mr Hart, who has held a watching brief on Northern Ireland on behalf of Mr Kerry since last summer, said he didn’t think the renewed violence would prompt any change in the US approach.

The US was committed to trying to stabilise the situation in Northern Ireland and “help any way we can regardless of the radical elements prone to violence”, he said.

"As you know scarcely a day goes by in the United States that some radical individual or group doesn't commit some violence," he said. "We, as Americans, always have to be very careful about finger-pointing where this is concerned."

The home of Northern Ireland Deputy First Minister Martin McGuinness in Derry was attacked by paint bombers on Sunday. This followed attacks last week on the car of a Sinn Féin member in Derry and the party’s billboards and posters in the city. Sinn Féin representatives have been further threatened and attacked this week. Mr McGuinness blamed Tuesday night attacks on the cars of two councillors in Derry on “anti-democratic dissidents”.

Police are separately investigating the murder of Mr Davison (47), a supporter of Sinn Féin's peace strategy, who was gunned down in the Markets area of Belfast on Tuesday morning. He is the most senior Republican supporter of the peace process to be killed since the IRA ceasefire of 1997.