Pressure is growing on the British government to free prominent republican Sean Kelly, who was jailed last month without explanation.
Sinn Féin has said Kelly has morked to defuse tensions in the republican Ardoyne area, which has been the scene of intense clashes over Protestant marches through the area.
Sinn Féin president Gerry Adams said this week that the continued imprisonment of Sean Kelly “throws petrol onto an already volatile situation”.
“The man should not be in prison and we made that very, very clear. To my knowledge, no one has given evidence around why the man was put in prison.”
Local assembly member Gerry Kelly urged people to attend protests in Belfast and Derry against the move.
“It is a disgrace that Sean Kelly continues to be interned,” he said. “Sean Kelly is actually being interned for trying to work positively in bringing about calm in north Belfast,” Gerry Kelly said.
“Yet in recent days Orange marchers have been forced through Catholic areas and loyalist gun gangs are openly using weapons and issuing statements of intent on the streets.”
Kelly, a former republican prisoner, was released on licence under the terms of the 1998 Good Friday Agreement. That licence was suddenly revoked last month by British Direct Ruler Peter Hain, apparently after Kelly was photographed at the scene of a riot in North Belfast.
Mr Kelly said that the treatment of Sean Kelly now “raises significant questions about the mentality of those British securocrats who may have triggered this off and certainly about the judgment of Peter Hain who signed the internment order”.
Local priest Fr Aidan Troy has also added his voice to nationalist demands for the British government to produce evidence or release Mr Kelly.
“Anywhere I had seen him he was trying to exercise some restraint, particularly on some of the young people during some of the disturbances in Ardoyne,” said Fr Troy, following a visit to Mr Kelly at Maghaberry Prison.
“I asked him truthfully, was there things going on I didn’t know about, anything happened that would have justified him going back to prison?
“His response was, as far as he was concerned, he had done nothing,” Fr Troy said.
“His presence at riots and his being photographed were all in an effort to try and exercise some restraint and never to provoke.”
However, DUP assembly member Nelson McCausland attacked Father Troy’s commments, which he said wer “distinctly unhelpful and disappointing”.
“I have no doubt that the secretary of state and the police have solid evidence.”