Several casualties as two helicopters collide mid-air in Australia

Two helicopters have collided mid-air killing four people on Australia's Gold Coast tourism destination, officials said, with images showing one of the aircraft's rotors lying on a sand bank.

Three other people are in critical condition, police said on Monday.

One helicopter lay flipped over on the sand a few feet from the shore. Its rotors lay a short distance away, images from public broadcaster ABC showed.

The other chopper appeared to be largely intact at the accident scene, which is near the popular Sea World marine theme park.

A bright yellow rescue helicopter had landed on the sand nearby, its rotors spinning, images of the aftermath showed as scores of rescuers spread around the area.

Several police and rescue vessels stood by just off the sandbank strewn with the wreckage of the two aircraft.

Investigation launched 

"Those two aircraft, when collided, have crash landed, and landed, on the sandbank just out from Sea World resort," said Queensland police service acting inspector Gary Worrell.

"As a result of that, four people have lost their lives today," he said. "Three others are critical in hospital."

Australia's transport safety bureau launched an investigation into the incident, which it described as a "mid-air collision".

Investigators were expected to arrive shortly to examine the wreckage and map the site, as well as recover components for examination, it said in a statement.

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