Five fishermen were forced to dive overboard today after fire engulfed their vessel as it sailed out of Belfast Lough.
The men were taken to the Royal Victoria hospital after being rescued from the freezing waters by another boat.
The Bellatrixvessel was still ablaze this evening and a 300-metre exclusion zone has been put in place around it amid fears that three gas canisters and a 300-litre diesel load could yet cause further explosions.
The vessel, which is registered in Kilkeel, is drifting toward the Co Down side of the coastline and police have cordoned off sections of the shore to prevent people gathering in the area.
Coastguard spokesman Mark Clarke said emergency services were allowing the fire to burn out.
“There’s just too great a risk of anyone going near it. This must have been a catastrophic fire that took hold very quickly.”
The boat had just left the harbour when the fire started around 1pm.
Mr Clarke said four of the five fishermen were released from hospital after being treated for smoke inhalation.