There have been two separate petrol bomb attacks on prison officers' homes in County Antrim.
They are the latest in a series of attacks linked to a prisoners' dispute at Northern Ireland's high security Maghaberry prison in County Antrim.
One prison officer's home in Carnmoney was attacked late on Monday.
A car outside the house was also set on fire.
In Ballyduff, a house that used to belong to a prison officer was attacked with petrol bombs.
Loyalist paramilitaries have denied being responsible for several attacks on the homes of serving and former prison officers in Northern Ireland.
In September, a review of safety at Maghaberry recommended separating republican and loyalist prisoners.
The move is being introduced in the wake of violent clashes between rival groups in Northern Ireland's high security prison and in the face of a "dirty protest" by a group of dissident republicans.