Mark Durkan: Had meeting with Sinn Fein president

"They have always remained active and we know that the issue is recently there have been a number of events that have given concern that the IRA was involved either directly or indirectly."

However, he also said there was also a credibility problem with the intelligence services.

However, Mr Adams again maintained that the IRA ceasefire was intact, and said people should focus on other issues.

Speaking after the 75-minute meeting, he said: "I am not really all that interested in getting into a media guessing game.

"What I do know is this and it's there on the public record that republicans have contributed hugely to this process."

Later on Tuesday, Ulster Unionist leader David Trimble is due to meet Secretary of State John Reid in London to discuss the state of the IRA ceasefire.

David Trimble: Wants clarification on status of IRA ceasefire

On Monday night, he held talks with the Irish Prime Minister, Bertie Ahern, after a unionist motion over alleged IRA activity failed to win support in the Northern Ireland Assembly.

Speaking after the meeting Mr Ahern said that he believed the IRA ceasefire was "very much in place".

The Ulster Unionist motion calling on the Northern Ireland secretary to assess the state of the IRA ceasefire failed on Monday.

Ulster Unionist leader David Trimble told the assembly he believed there was enough information for the secretary of state to act against the IRA.

Mr Trimble claimed there was evidence of the group's involvement in Colombia and intelligence that republicans were behind the recent murder of Barney McDonald in County Tyrone.

John Reid: Asked to assess IRA ceasefire

Ulster Unionist leader David Trimble said: "The important point to bear in mind in regard to Castlereagh and the Dungannon killing (of Barney McDonald), is that yes there is suspicion, yes there is intelligence... but we do not yet have hard evidence.

"But that is precisely what the secretary of state can act on."

Sinn Fein's Gerry Kelly told the assembly that it was British intelligence behind the security breach at Castlereagh.

Speaking on Tuesday, the leader of the Progressive Unionist Party, David Ervine, said he doubted Sinn Fein knew what the IRA was doing.

He said that he was seeking a meeting with Sinn Fein leader Gerry Adams, and warned that the process was heading towards a crisis.

Last October, Dr Reid said the government no longer recognised the ceasefires of the UDA/UFF - the largest loyalist paramilitary organisation - and the smaller, splinter group, the Loyalist Volunteer Force.

It followed the murder of a County Armagh journalist and an upsurge in street violence.