WELLINGTON (AFP) - New Zealand police said on Tuesday they were questioning two boys, aged 12 and 13, over the fatal stabbing of a shop keeper in Auckland.

Police said the boys were taken into custody after Arun Kumar, 57, was stabbed in the neck early Tuesday morning.

They said officers were called to reports of a robbery at the shop in suburban Henderson at about 7.30am local time and found Kumar seriously injured. Attempts to save him failed.

Detective-inspector Bruce Scott said the boys, who were known to police, were picked up a short time later.

"It is shocking to us that kids so young could be involved, or possibly involved, in something like this," he told reporters, saying nothing was taken in the apparent robbery gone wrong.

No charges have been laid.

New Zealand's youngest convicted killer was a 12-year-old boy who admitted to manslaughter in 2001 over his involvement in the stabbing death of a pizza delivery man.