The Northern Ireland Fire and Rescue Service says that blaze at Glentaise Drive in Ballycastle was started deliberately.
Two houses have been badly damaged and a further two homes sustained slight smoke damage in an arson attack in Ballycastle, County Antrim.
The fire in Glentaise Drive was reported to the Northern Ireland Fire and Rescue Service (NIFRS) shortly after 08:00 BST on Monday.
Residents got out before crews arrived.
NIFRS Station Commander Noel Darley said: "After initial investigation, we're treating the fire as a deliberate fire."
He said it appeared that the fire "started in the roof void of one of the properties and spread to an adjoining property".
"The prompt response from the Ballycastle crews undoubtedly prevented much more substantial fire spread to a further four adjoining properties," Mr Darley added.
Two fire appliances from Ballycastle Fire Station and one from Coleraine Fire Station were deployed to the scene.
They left the scene shortly before 09:45 BST and the arson investigation has been passed through to the Police Service of Northern Ireland (PSNI).
