Three backyards caught fire on Churchill Cres in Whanganui this morning.
Fire and Emergency Whanganui was notified of the fire at 11.50am.
Senior station officer Bryan Coskerie said an elderly man was using an incinerator to burn some rubbish.
"He was unaware of the complete fire ban. He left the fire unattended for a few minutes and when he came back, three backyards were ablaze."
Francisca Webby, who lives at one of the properties that caught fire, said the fire spread within minutes.