Around 100 prisoners were let out of their cells causing a serious risk to prison staff.
The incident at Maghaberry over the weekend was reportedly caused by an electrical fault.
An officer contacted the Newsletter and claimed the doors on the cells 'unexpectedly opened'.
The Northern Ireland Prison Service confirmed there were two fire incidents on two wings at the high security facility.
Prisoners set fire to rubbish at Bush House on Saturday and Erne House on Sunday.
No inmates or staff were injured and no evacuation was necessary.
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