RUC sources are indicating that a paramilitary group could have been responsible for the theft of up to £250,000 in Co Tyrone yesterday. In a carefully planned operation, five armed and masked men held up an armoured Royal Mail van at a remote valley in the Sperrin Mountains.
They took the postmen hostage and drove the van to a nearby forest where they removed what police described as a "substantial amount of cash".
An RUC spokeswoman in Belfast refused to comment on who police believed was responsible for the attack.
"The investigation is continuing. No group has claimed responsibility. I have no idea what line of inquiry detectives are following," she said.
However, police sources in Co Tyrone said the robbery was most likely the work of paramilitaries. It was too well organised for local criminals who would not have the same expertise or access to weapons, they said.
The van was stopped in an isolated spot on the Plumbridge-Draperstown road. The immediate vicinity is republican, although the wider surrounding area is loyalist. On the republican side, suspicion fell mainly on the Provisional IRA, although the Continuity IRA cannot be ruled out.
The hardline Loyalist Volunteer Force, which is anxious for funds, could also have carried out the robbery, although many observers doubt whether it would be capable of such a well-organised operation.
If it is established that the IRA was responsible, then pressure will mount for Sinn Fein to be expelled from all-party talks. The UUP MP, Mr Willie Ross, said last night that if IRA involvement was proved, Sinn Fein would clearly be in breach of the Mitchell Principles of democracy and non-violence and should be expelled from talks.
The robbery happened around 11 a.m. yesterday. The robbers parked a van in a dip on the roadway. When the driver of the Royal Mail vehicle stopped to avoid colliding with it, the men rushed it.
The driver and his co-driver were ordered into the nearby Goles Forest. Their van was driven into the forest by one of the masked gunmen. The robbers then moved the cash bags into their vehicle and drove off, taking the driver of the Royal Mail van with them. He was tied up and left, along with the getaway vehicle, in a lay-by farther down the road.