The United States Coast Guard announced on Friday, that it was searching for a helicopter with seven people on board.
It said the aircraft went missing off the coast of Hawaii.
The chopper was on a tour of the coast of the northwestern island of Kauai, where the weather conditions were said to be “challenging.”
The helicopter was carrying a pilot and six passengers, two of whom were believed to be minors, a statement from the Coast Guard said.
A boat and a helicopter were sent to search the area, when its owner raised the alarm around 40 minutes after it was due back on Thursday evening, the release added.
“We have trained crews responding and on scene searching for any signs of the helicopter and those aboard,” said Petty Officer 1st Class Robert Cox, according to local media.
Visibility was low and there were blustery winds, he added.
The chopper has an electronic locator on board, but no signals have been received, the Coast Guard also said.
The Coast Guard helicopter and crew are being supported by the US Navy Helicopter Maritime Strike Squadron 37 at Kaneohe Bay.
A Coast Guard vessel and crew were also launched from Honolulu.
Helicopter tours are common above the island of Kauai, which is mainly a state park.