Two people are dead and another is in hospital after a boat capsized on the Rangitīkei River bar.

Police, St John and Fire and Emergency NZ were called to Tangimoana Beach around 8am on Monday and remain on site.

Hato Hone St John said two ambulances, an operations manager, and one rapid response vehicle attended.

"One patient has been transported to Palmerston North Hospital in a moderate condition."

Police confirmed two others had died.

In a statement, the Coastguard said its National Operations Centre was notified of a capsized vessel on the Rangitīkei River bar just after 8am, with reports of three people in the water.

"Volunteers from Coastguard Manawatū responded with their jet ski Blue Rescue and rescue vessel Kevin Morris II."

Surf Life Saving said one person made it back to shore themselves, while the remaining two were brought in by life guards.

Police expect the deaths to be referred to the coroner.