The Progressive Unionist Party, the UVF's political wing, has said it has "no doubt" that a bomb factory discovered in north Belfast was linked to the paramilitary group.
But a PUP Assembly member, Mr David Ervine, insisted that the UVF was not involved in recent pipe-bomb attacks against Catholics which previously had been blamed solely on the UDA.
On Sunday the RUC found 11 pipe-bombs, home-made explosives, an under-car boobytrap bomb and a primed bomb consisting of 20lb of explosives packed into a fire extinguisher, at a flat in Ross House in the Mount Vernon area. This is staunch UVF territory.
There have been about 50 pipe-bomb attacks by loyalists so far this year.
Mr Ervine admitted that the factory belonged to the UVF, saying: "I have no doubt that it was their material. The question being asked is, what for?"
He suggested the factory was linked, not to recent sectarian attacks, but to the loyalist feud which formally ended last month. The UVF had begun an investigation and when he was told the outcome "the people of Northern Ireland will hear it loud and clear."
The RUC yesterday put the materials on display and said the find had undoubtedly saved lives. The Chief Constable, Sir Ronnie Flanagan, said it had been a substantial discovery.
Nationalist politicians welcomed the find but also expressed concern.
An SDLP Assembly member, Mr Alban Maginness, said: "I am very disturbed to hear that booby traps for placing underneath cars were also found. If they had been used, they would have extended this campaign in a very, very significant way."
A Sinn Fein Assembly member, Mr Gerry Kelly, said the authorities should admit the UDA ceasefire was over.
An Ulster Unionist MP, Mr Cecil Walker, congratulated the police for thwarting "the potential for a sustained campaign of violence".
There were further pipe-bomb attacks early yesterday. Two were aimed at family homes at Broughshane in Co Antrim.
The first device was thrown at a house in Artoughs Park and the second at a property in The Commons. Neither exploded.
Police in Belfast were also investigating the throwing of two improvised devices over the peace line from the nationalist side in west Belfast early yesterday.
The RUC said large Chinese fireworks with nails wrapped round them were thrown over the line into Workman Avenue in the Springfield Road area. Neither exploded.
Two men and a woman escaped injury in a gun attack on a house in south Belfast early yesterday. Shots were fired through the bedroom window of the house in Rossdale Road in the Four Winds area.
In a follow-up operation, the RUC discovered a shotgun and several cartridges in nearby Finsbury Crescent. Loyalists are believed to have been responsible, and police are investigating.
The security forces found a crater by the railway line just outside Newry, Co Down. The RUC said it believes it was caused last Wednesday by a bomb containing 100lb of home-made explosives.
Dissident republicans are understood to have been responsible.