Israeli police said Sunday they have arrested several Jewish suspects over an arson attack last month at a shrine where Christians believe Jesus performed the miracle of loaves and fishes.

"Several Jewish suspects have been arrested for the burning of the church and the Nazareth court has decided to extend their detention for the purposes of the investigation," police spokeswoman Luba Samri said in a statement of the overnight arrests.

Police did not provide a number, but an ultra-nationalist organisation said three young Jews had been arrested.