A woman was seriously injured after being struck by a humpback whale tail fin during a whale-watching trip off the west coast of Australia, local media reported in Australia today.

Media reports said the accident occurred while the young woman, 29, was swimming near the whale. She had broken ribs, suffered internal bleeding, and was flown to a hospital in the nearby city of Perth.

The Australian "ABC" radio quoted a hospital spokesman as saying that the woman's condition is serious but stable. The accident occurred at Ningaloo Reef, about 1,200 kilometers north of Perth.

Humpback whales can be up to 15 meters long. These whales are known to be peaceful, despite instructions given to swimmers in Australia to keep 100 meters of such whales if possible.

Three years ago, the authorities also warned that swimming alongside a humpback whale at a reef is very dangerous, as Danny Rob, a whale conservation official, says it is only a matter of time before someone is exposed to abuse.