A search is continuing for a nine-day old baby in Belfast Lough after the child and its mother went overboard shortly after 6pm.
Although the woman has been recovered from the water and brought to hospital it is understood that the baby remains missing.
The Bangor Life Boat team are carrying out the search with assistance from the Dublin-based coastguard helicopter which was tasked to participate in the search at around 6.30pm.
The woman and baby had been travelling on the Stena Super Fast VII vessel when the incident occurred.
A spokesman for the PSNI said tonight they were in attendance at the scene along with its partner agencies.
“It was reported that two people fell into water from a ferry. One person was rescued and treated for suspected hyperthermia.
“A search is ongoing for a second person. This is believed to be a young child,” the spokeswoman said, adding that anyone who witnessed the incident is asked to contact the PSNI.
A spokesman for the Northern Ireland ambulance service said they had treated the female casualty.
“She had been in the water for a while so you can understand that with the coldness of the water she would have been hypothermic,” he said.