A major search operation is underway after a private medical jet carrying six people vanished while flying from Bermuda to Boston.

The US Coast Guard deployed aircraft and vessels to search waters near Nantucket after authorities lost contact with the Canadian-registered Gulfstream jet early on Saturday.

The aircraft, which was being used as an air ambulance, was carrying four crew members and two passengers when it disappeared.

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The Federal Aviation Administration alerted the Coast Guard after contact with the aircraft was lost, a Coast Guard spokesperson said.

Six people on board

The jet had departed Bermuda’s LF Wade International Airport overnight and was bound for Boston Logan International Airport in Massachusetts.

Bermuda airport operator Skyport confirmed six people were aboard the medical transfer flight, including four crew members and two passengers.

Four of those on board are Canadian citizens, according to Canadian Transport Minister Steven MacKinnon.

Mr MacKinnon said Transport Canada was closely monitoring the situation and working with authorities involved in the search and rescue operation.

The identities of those on board have not been released.

Search underway near Nantucket

US Coast Guard air and surface crews have been sent to search for the missing aircraft near Nantucket, an island south of mainland Massachusetts.

Weather conditions around Nantucket were reported to be clear on Saturday morning, according to AccuWeather.

It was not immediately clear what caused authorities to lose contact with the aircraft or whether any distress call had been made before it disappeared.

The flight was expected to take almost two hours after departing LF Wade International Airport for Boston, according to FlightAware.

Authorities are continuing to search for the aircraft and the six people on board.

With AP