One person was confirmed dead and two others were missing Thursday after a helicopter crashed into the ocean near the US state of Hawaii, police said.

The helicopter, belonging to Ali'i Kaua'i Air Tours and Charters, crashed in waters about a quarter mile off the coast of Na Pali.

The Kauai Police Department said in a statement that it received a report of the incident around 13:20 p.m. local time (23:30 GMT).

Hikers along the Kalalau Trail witnessed the helicopter crash and reported the incident to police Thursday afternoon, according to the statement.

"Our hearts go out to the families affected by this tragedy. We will continue to work with our partners to locate the missing persons and provide support during this difficult time," said Police Chief Todd Raybuck. "Our multi-agency response remains focused on search and rescue efforts."

The mayor, Derek Kawakami, also expressed his condolences to the families. "While we do not know all the details surrounding the incident at this time, we do know that our first responders are doing everything they can in this emergency operation. Our thoughts and prayers are with the families of all involved," he said./AA