A man has leg and hand injuries after a gunman fired a sawn-off shotgun into a house north of Auckland.

The gunman went to the house on a residential street in Whangaparoa, 40km north of Auckland, just before midnight on Wednesday, police say.

There was a confrontation between the gunman and residents before a shot was fired at the house, smashing a window, and the gunman took off.

Others at the house were uninjured.

Rodney Police said they were looking for a Caucasian or part-Maori man in his 30s, of stocky build and about 1.65m tall, wearing a dark coloured beanie, faded blue jeans and a thick fleecy woollen jacket.

The weapon was described as a sawn-off shotgun, less than a metre in length with a black dull pitted barrel and a wooden handle.