SYDNEY - It's got a big yellow dog, sharks, a dead dugong, attracted millions of viewers on YouTube and you couldn't make it up.    

A video grab from footage shot June 1, 2011 shows two dogs swimming after one of them dived underwater and appeared to bite a shark, in the shallow waters in the west Australian town of Broome. Cameraman Russell Hood-Penn captured the moment on film and shouted "the dog's biting the shark" as the dog dived under the water towards the shark. [Photo/Agencies]

Video footage of a dog attacking a shark under water on the Australian coast has "gone viral", becoming a top Internet hit.

The footage shows two dogs swimming in the ocean near the West Australian town of Broome, about 1,650 km (1,025 miles) northeast of Perth.

The dogs appear to be herding several sharks towards shore, when one suddenly ducks under the water and attacks a shark.

"The dog is biting the shark," said Russell Hood-Penn in the voice-over as he video-taped the incident. "That is unbelievable. I've seen it all now."

Hood-Penn placed the footage on video-sharing website YouTube (http://www.youtube.com/watch?v=6HyIZh5BQZY), where it has been viewed more than 27 million times.

When the camera pans out, a dead dugong (a large marine mammal similar to a manatee) can be seen beached on the shore and Hood-Penn speculates that is the reason the sharks are circling so close to shore.

At the end of the video the dog emerges from the ocean and shakes the water from its fur. There was no word on the fate of the shark.