There has been flooding in parts of Larne, Belfast and Carrickfergus following heavy rain overnight.
A discarded Christmas tree may have blocked a culvert in an east Belfast street leading to heavy flooding.
Several roads were closed and the police were advising motorists to drive with caution.
More than 50 firefighters were called to the Castlehill Road area on Sunday and several homes were evacuated.
A number of homes were evacuated in the Castlehill Road area of east Belfast. Houses were threatened by about three feet of water after a drain blocked.
Northern Ireland Water says it is investigating the causes of flooding in parts of the city following heavy rainfall.
Carrickfergus and Larne were also affected by the rain. Several roads were closed.
In east Belfast, the water rose to about 3ft after the drain was blocked, perhaps by a Christmas tree.
Manholes were forced open by the pressure of the water and the fire service had to pump the water away.
Manholes were forced open by the pressure of the water and the fire service had to pump the water away.
Fire Service group commander Kevin Synnott said: "There is a high risk to anybody walking in the area, you are walking through water and there is a great big hole in the ground."
Manholes were forced open by the pressure of the waterAt least one house was flooded at Lisavin Drive in east Belfast's Sydenham area.
The road has been closed between the Newtownards Road and Massey Avenue.
Police also warned motorists to drive with extreme care on the the Beltoy Road and Marshallstown Road in Carrickfergus.
Manholes were forced open by the pressure of the waterAt least one house has been flooded at Lisavin Drive in east Belfast's Sydenham area.
There were also reports of flooding at Magazine Street in Larne, and east Belfast's Parkway, Alexander Road, the Knock dual carriageway and Ballygowan Road.
Police have also warned motorists to drive with extreme care on the the Beltoy Road and Marshallstown Road in Carrickfergus.
There are also reports of flooding at Magazine Street in Larne, and east Belfast's Parkway, Alexander Road, the Knock dual carriageway and Ballygowan Road.
Peter McMurray, who lives in Sydenham described the extent of the flooding in his street.
"It takes up about half the street quite easily," Mr McMurray said.
"One of the neighbours has a 4x4 and it's coming up to just under the door of his car."
"Now the rain's actually stopped, but if there's any more rain people are obviously getting uptight about it."
Meanwhile, the Gaelic Life McKenna Cup clash between Down and University of Ulster at Jordanstown has been postponed because of a waterlogged pitch in Newcastle.
