Martin McGuinness has called on people not to celebrate the death of Baroness Thatcher.
Street parties were held in republican parts of Londonderry and West Belfast following the former prime minister's death.
Mr McGuinness, Sinn Fein's Deputy First Minister at the Northern Ireland Assembly, tweeted: "Resist celebrating the death of Margaret Thatcher. She was not a peacemaker but it is a mistake to allow her death to poison our minds."
Unionists like DUP First Minister Peter Robinson have praised her commitment to the Union but Sinn Fein president Gerry Adams accused her of pursuing "draconian, militaristic" policies which prolonged the conflict.
Her uncompromising stance over the hunger strikes in the Maze/Long Kesh prison in 1981 defined her as a republican hate figure. She refused to back down on her policy of criminalisation of IRA inmates. A total of 10 prisoners starved themselves to death in an attempt to secure prisoner of war-type privileges.
Baroness Thatcher also took a steadfast approach against any wider settlement with the IRA as violence regularly afflicted Northern Ireland.
An IRA bomb in 1984 exploded at the Conservative Party conference in Brighton, killing four delegates and seriously injuring many others in an attempt to assassinate the premier.