A medical evacuation aircraft carrying six people has gone missing after departing Bermuda bound for Boston, prompting an urgent search operation over the Atlantic.

The flight lost contact with air traffic controllers during its journey from the island, and authorities on both sides of the Atlantic have been alerted. The aircraft was reportedly transporting a patient along with medical personnel and crew when it vanished from radar.

Bermuda's emergency services are understood to be coordinating with United States Coast Guard and aviation officials as search efforts focus on the flight's expected route across open ocean. The roughly 770-mile journey between Bermuda and Boston crosses some of the most remote stretches of the western Atlantic, complicating rescue efforts.

Officials have not yet released the identities of those on board or details about the medical condition of the patient being transported. The type of aircraft and the operator involved have also not been formally confirmed.

Medevac flights are a lifeline for Bermuda residents requiring specialist treatment unavailable on the island, with patients regularly airlifted to hospitals in Boston and other US cities. The disappearance has sent shockwaves through the local community, where such flights are a familiar and essential service.

Authorities say updates will be provided as the search develops. Anyone with information is asked to contact Bermuda's Rescue Coordination Centre.