In a separate development last night, it was announced the talks have been postponed from Wednesday until Friday, apparently because the Sinn Fein president, Gerry Adams, has secured an appointment at the White House on Tuesday.
Security sources said ''a top IRA team'' was involved in an abortive raid at a petrol station in west Belfast yesterday morning. Five arrests were made during and after the incident. The RUC said a replica firearm, masks and money had been recovered.
Last night, republican sources said two of those held were republicans. But they claimed they had no connection with the incident.
The attempted robbery happened only two hours before John Major warned there must be ''no more robberies'' and that republicans must commit themselves to exclusively democratic methods. The incident comes three weeks after a postal worker was killed during an armed raid in Newry, Co Down. The IRA later admitted that its members were responsible for the raid, but blamed it on a problem in its chain of command.
The senior republican Martin McGuinness is now due to lead a Sinn Fein delegation into talks with British government representatives in Belfast on Friday. Before then, the authorities are likely to want full clarification of the west Belfast incident. There was no official British comment last night.
Mr Major said in in London yesterday that the Government was offering a fair place in political life to those who committed themselves exclusively to peaceful methods. He said: ''But by exclusively I do mean exclusively - no more punishment beatings, no more robberies, no more racketeering, no more blackmail.''
After the Newry robbery, the IRA said those involved had been acting on instructions but maintained the leadership had not approved the raid.
This explanation suggested a figure in the organisation senior enough to give instructions had not grasped the fundamental point that the use of firearms had not been sanctioned. Clarification of this by the IRA brought relief to both the British and Irish governments, since it seemed to have been established that the IRA was committed to stopping the use of guns, thus ruling out any further armed robberies.
Yesterday's raid means republicans will again face pressure to say whether this was a rogue operation or one which had been sanctioned. Given the delicacy of the situation, and the importance which Sinn Fein attaches to next week's talks, armed action at this point would suggest that the republican movement is facing a serious shortage of funds.
The Newry killing's importance was shown by the fact that within hours the Irish government said it was halting the early release of republican prisoners from southern jails. The Northern Ireland Secretary, Sir Patrick Mayhew, said at the time that he very much hoped the incident would not affect the timetable for talks.
But while all sides are hopeful of moving the peace process on, the latest raid is too serious to leave unclarified. A main topic in the talks is set to be the IRA's arms. Sir Patrick said yesterday, before news of the west Belfast raid, that the talks would depend on proposals for disarming the IRA.