Two Northland brothers who ran off from their grandparents' house and went missing overnight has police urgently calling for any sightings.

The boys Kyryn Hilton, aged 11, and 9-year-old Alexander Hilton were last seen at their grandparents' house at Karetu, 10km east of Kawakawa about 8pm on Wednesday.

Family started searching but the boys were not found and police were contacted about 8.45am today.

Senior Sergeant Cliff Metcalfe said the longer the boys were missing, the more concern for their safety grew.

"We would have expected them home by now. It's a possibility they are staying with someone or have gone into the bush."

He said it was a possibility they would try to make their way to Whangarei.

"Anyone who has seen these two or knows where they are should contact police immediately."

The local school teacher had also searched the school grounds today but had not found them.

Kyryn was last seen wearing a grey-coloured Hunting and Fishing fleece, grey shorts, black socks and black slip on Nike sandals. He is of stocky build and has no hair.

Alex was wearing a black shirt and shorts and a cap.

Family have put out a call on Facebook for any sightings of the brothers.

"They are very young and we just want them home safe," an aunty said in the post.
She said they could possibly have bikes.

If you can help call Whangarei police station on 09 430 4500 or contact your local station.