Two people have died after a boat with 11 onboard capsized off Goose Bay in Kaikōura.

Kaikōura mayor Craig Mackle said the boat collided with a whale.

Mackle said the boat had a group of women aged over 50 on board and waters were calm at the time of the incident.

Some have been rescued and were taken to the local medical centre but their conditions were not yet known he said.

Mackle told Chris Lynch three people were still missing and helicopters were circling the waters.

However, a Palmerston North-based rescue helicopter was heading back to its base just after 3.30pm.

“It’s just awful, I never thought we’d ever be dealing with something like this” Mackle said.

It’s understood the group had hired a local fishing charter boat.

An image on social media shows a number of people on top of the upturned boat, awaiting rescue.

Members of Coastguard Kaikoura were leading the operation with police.

Councillor Lisa Bond said, “what happened was shocking and appeared to be a freak accident which would really rock the close-knit community.”

Kaikōura volunteer firefighters were helping with the search.

Police divers from Wellington have arrived at the scene and local boats and local divers were helping with the rescue.

A local said a Department of Conservation boat was being deployed for “crowd control on the water” and to look for the injured whale.

South Bay has been shut off at the turn-off for anyone but residents