A wind farm formerly owned by Seán Quinn’s family has been targeted by arsonists in Co Fermanagh.
Police said an electrical substation at the property on Ballyconnell Road in Derrylin was set alight on Thursday evening.
No one was injured but the fire caused substantial damage.
It was the latest in a series of attacks on property once belonging to the former Quinn group.
The incident occurred sometime between 6pm and 7pm on Thursday.
This latest attack is the 18th since the Quinn group was taken over.
While there has been no more than speculation about who might be responsible, Mr Quinn has previously dissociated himself and his family from any such actions.
So also have those who have staged peaceful protests in sympathy with the plight of the Quinn family.
The Police Service of Northern Ireland is appealing for witnesses to the attack.
It wants anyone who was in the area at the time of the attack or anybody who has any information to contact them at 08450-6008000. Alternatively, anyone with information can contact the confidential Crimestoppers service at 0800-555111
A PSNI spokeswoman said: “At this stage police believe that the fire was started deliberately.”
Workers at Quinn group factories in the area staged a one-day walkout on Monday following the jailing of Mr Quinn last week.
Protesters used tractors and other agricultural vehicles to block the entrances of the cement and glass plants in Derrylin and just across the Border in Ballyconnell, Co Cavan.
They called for immediate mediation between the former Anglo Irish Bank and the Quinn family over the long-running debt row that culminated with the imprisonment of Mr Quinn a week ago.
Protesters have demanded Mr Quinn’s release while the talks take place.
The 66-year-old was jailed in Dublin’s High Court for contempt of court in relation to proceedings related to alleged hiding of assets from the Irish Bank Resolution Corporation, formerly Anglo Irish Bank.