Four people have been left dead and others in critical conditions after two helicopters collided near a well-known tourist strip, Seaworld, on Australia’s Gold Coast in the early hours of Monday.

Police said initial investigation indicated that the incident occurred when one of the helicopters was taking off and the other was landing in a collision that authority said happened at about 2:00 p.m. local time (04:00 GMT).

The deceased and three other passengers in critical conditions were occupants on the same helicopter while five out of six passengers in the other helicopter, which made a late emergency landing, only suffered minor injuries.

The Australian Transport Safety Bureau (ATSB) confirmed that the crash occurred near a tourist strip known as Main Beach, about 75km (47 miles) south of Brisbane. 

Seaworld park offers sightseeing helicopter flights for tourists, as well as carrying out other charter operations, with the main access road to the park now closed by authorities.

Gary Worrell of the Queensland Police Service said, “It’s a difficult scene. Due to the area it’s located on, on the sandbank, it was difficult to gain access, to get our emergency services to the scene to manage it appropriately.”

Investigation at the crash site by the ATBS is in progress.