A 21-year-old woman has been attacked by a shark in Great Barrier Reef waters off Cape Grenville, the ABC report.

The incident reportedly happened on Sunday (28th July) at 6:30pm.

The young woman suffered a serious injury to her lower right leg.

A spokesman for the Royal Flying Doctor Service said they flew the woman to the Lockhart River Medical Clinic before she was admitted to Cairns Hospital.

A second person was also reportedly flown to Cairns hospital suffering shock.

(Source: ABC)