Two serious house fires have broken out in the North Island.

One is on Rena Place in West Harbour, Auckland. The other is on Showground Rd, Paengaroa, east of Tauranga.

Fire Service northern shift manager Paul Raddem said both houses are "well involved" in flames. He did not believe the fire was posing a threat to any person or other structure.

Three crews are at the West Harbour fire, they were called out at 7.45pm. Four crews are at the Paengaroa blaze, they were called at 7.30pm.