Deputy First Minister Martin McGuinness condemned the fatal shooting of Tommy Crossan, saying:
The people behind this killing are criminals and will further no cause through this shooting. Whoever carried out this act has nothing to offer the community and have no role to play in our future.
Dialogue not destruction is the way forward and while there may be a small minority of people who are trying to promote division and heighten tensions, let's be very clear, they will fail.The peace process is rock solid and all right thinking people across the community oppose and reject the actions of the people behind this murder.
Lord Tebbit has come under fire after suggesting he hoped Sinn Fein politician Martin McGuinness would be "shot in the back".
The former Conservative chairman, who was himself injured in the 1984 Brighton hotel bombing, suggested Mr McGuinness' presence yesterday at a state banquet with the Queen might anger hardline Republicans.
"There's always the possibility that a member of the Real IRA will be so outraged by Mr McGuinness bowing to the Queen that they might shoot him in the back for it. We can but hope," he said.
Sinn Fein leader Gerry Adams expressed outrage at the comments, saying:
"To publicly advocate the assassination of Deputy First Minister Martin McGuinness is a shocking throwback to a violent past from which we are seeking to move on."
Sinn Fein President Gerry Adams has hailed a "new and positive relationship" between "all of Ireland and Britain" as it was announced that Martin McGuinness would attend an Irish state banquet hosted by the Queen.
"While Martin McGuinness's involvement in President Higgins's state visit may not be welcome by opponents of change, it is yet another example of Sinn Fein's commitment to an inclusive future based on tolerance and equality," he said.
He continued: "This decision may cause difficulty for some Irish republicans in light of ongoing difficulties in the north (of Ireland) but I would appeal to them to view this positively in the context of republican and democratic objectives and the interests of unity and peace on this island."
The banquet, in honour of Irish President Michael D Higgins, will be hosted at Windsor castle next week.
Northern Ireland's Deputy First Minister and ex-IRA commander Martin McGuinness will attend a state banquet at Windsor Castle in honour of the Irish president hosted by the Queen, it has been confirmed.
Stormont's Deputy First Minister Martin McGuinness said should the First Minister resign it would achieve "absolutely nothing".
Asked what he thought of Peter Robinson's threat to leave his post, he said: "I have to ask the question, what would that achieve?
"It could lead to an election and Sinn Fein has no difficulty with elections ... but what would that achieve? In my view absolutely nothing."
Mr McGuinness urged politicians to "stop the grandstanding" and stressed "steady leadership, responsible leadership" is needed going forward.
Stormont's Deputy First Minister will hold talks with the Northern Ireland Secretary as a political crisis triggered by the collapse of the Hyde Park bombing case continues to threaten the future of the devolved administration in Belfast.
Sinn Fein's Martin McGuinness and Theresa Villiers are set to meet at Stormont Castle to discuss the controversy that prompted First Minister Peter Robinson to threaten to resign.
The Democratic Unionist leader has effectively given the UK Government 24 hours to respond to his demand for a public inquiry into secret letters sent to IRA suspects that assured them they would not be prosecuted.
Northern Ireland's Deputy First Minister Martin McGuinness has condemned a reported explosion in Lurgan, County Armagh.
Mr McGuinness wrote on Twitter:
Bomb in Lurgan has to be condemned, Anti Peace extremists living in Fantasy World.attack futile,won't change a thing.NO Going Back. SIOCHAN
Martin McGuinness has resigned as Mid-Ulster MP.
He said this was in line with Sinn Fein's commitment to end double jobbing and planned to concentrate on his job as Stormont MLA and deputy First Minister.
Francie Molloy will run for the seat in his place.
Mr McGuinness said: "I am resigning as MP but I have no intention of leaving Mid-Ulster. South Derry and East Tyrone have suffered immensely as a result of the conflict.
"I will always be grateful to the people of this area for trusting me to represent them and their interests.
"I will of course continue to represent the Mid-Ulster constituency in the Assembly. I am honoured to do so both as an MLA and as deputy First Minister in equal partnership with Peter Robinson."
He was elected MP for Mid-Ulster in 1997.
The First Minister of Northern Ireland Peter Robinson praised US Secretary of State Hillary Clinton for her "instrumental" role in the peace process.
He said: "Very often, we will sit down, and somebody will mention someone who has claimed to be instrumental in the peace process, and Martin and I look at each other, and say 'Do you know them?'
"But you are one person who has consistently helped us. You have been a great friend to Northern Ireland."
Referring to the assassination off Co Sligo in the Irish Republic, he said he told the royals that he recognised they had lost a relative.
"I said to the Queen and the Duke they too had lost a loved one," he said.
Mr McGuinness revealed some of the detail of the private meeting during a talk show on RTE television.
The killing was discussed briefly after an historic handshake between the pair which has been hailed as a watershed moment in Anglo-Irish relations.
Mr McGuinness has not discussed any of the detail of the meeting until now. When he left the theatre he would only say that the Queen was very nice and that he was still a Republican.