SINN Fein has called on the INLA to lift its threat to target Orangemen and members of other loyalist institutions if any more marches are forced through nationalist areas.
An SF councillor, Mr Chrissie McAuley, said the "opportunistic" threat heightened sectarian tensions and diverted attention away from the British government's "irresponsible" decisions.
The INLA, in its statement issued yesterday, said it had been "engaged in operations in defence of besieged nationalist communities", which it claimed had resulted in RUC and British army casualties.
The statement said that if the march on the Ormeau Road happened on Sunday it would not be "without great cost".
Violence erupted in the North again last night when a minibus was hijacked by masked and armed men on the Dublin Road near Newry shortly after 11 p.m. Two beer kegs were put on board and the driver was forced to drive the vehicle to the British army's permanent vehicle checkpoint outside the town. A security alert continued until early today.
Youths abandoned a car outside a police post in Corry Square in Newry, claiming it contained a bomb. In Strabane, Co Derry, four shots were fired at RUC officers on a mobile patrol at Carlton Drive shortly before midnight. And in Crossmaglen, Co Armagh, 26 petrol bombs were hurled at the RUC station. No injuries were reported in either incident.
The Al between Dublin and Newry remained closed early today due to a burning barricade. Several vehicles were also hi-jacked and set ablaze in Belfast and in Newry last night.
In Lurgan, Co Armagh, yesterday, a lorry containing flammable chemicals was hijacked in Victoria Street and driven on to the Kilwilkee estate at lunchtime. The police eventually recovered it intact but said if it had been set alight it could have caused a chemical explosion and killed many people.
Rail services between Dublin and Belfast were cancelled last night following the burning of an Iarnrod Eireann train in Newry yesterday. A company spokesman said the resumption of services would be considered this morning.
A group of masked men, some armed, ordered passengers off the train as it stopped in Newry. They then threw petrol bombs into the carriages.
The Iarnrod spokesman said some passengers elected to return to Dundalk rather than continue their journey by bus.
He said initial indications were that the damage to the carriages was superficial and would probably cost "only a few thousand pounds" to repair.
This was the second attack on a train in Northern Ireland in three days. A six-carriage train was burned out in Lurgan on Sunday after masked men started a fire.
The cost of the damage in the North in recent days is thought to be around Pounds 10 million, with public transport and small businesses bearing the brunt.
Eighteen buses have been burned since Sunday. Within one hour in Belfast on Monday night six buses were set alight and services were stopped at around 7.30 p.m.
According to the RUC, the security forces came under attack on 776 separate occasions over the past four days and 60 RUC officers have been injured. At least 50 people have reported injuries to the police but the total is said to be much higher.
The security forces have fired more than 2,400 plastic bullets and there have been over 1,500 petrol bombings. More than 350 vehicles have been hijacked.