This is the shocking moment a K9 mauled a handcuffed suspect's arm while a police officer unsuccessfully tried to pull it away.

The man arrested in San Diego, California, was left with a large open wound after the dog pounced on him and sank its teeth into its forearm.

Angel Nunez, captured the incident on his way to work, and posted the video to Facebook.

'This K-9 officer had no control of his K-9,' he captioned it.

'There is something definitely wrong with this picture. The officer doesn't seem to have the proper training. Also that dog is not well trained.'

Three police officers were present when a K9 bit and twisted a man's arm on the sidewalk in San Diego, California

The attack unfolded on Monday afternoon. While many believed the suspect may have provoked the dog, a commenter posted a video of how the incident initially unfolded seconds before Nunez's clip.

The handcuffed man appears to have been in conversation with the police officer. It's unclear what they talked about before the dog pounced on the man, forcing him to the ground. He then repeatedly says 'okay, okay' while the officer yells, 'give me your hand!'

Nunez's clip then shows the K9 biting the suspect, who is screaming in agony, while the officer unsuccessfully tries to get the animal off.

Within a few seconds, blood starts gushing out of the man's arm. The video then shows two officers who arrive at the scene to hold the suspect's legs down. Throughout the video the suspect repeatedly screams, 'I am comfortable!'

A bystander then asks: ' You have no control of your dog whatsoever? Are you kidding me?'

The incident occurred on Monday afternoon. The handcuffed man appears to have been in conversation with the officer before the dog pounced

The K9 dog bit the man's hand for about 30 seconds, while the officer unsuccessfully tried to get the animal off

Another adds: 'You guys have three versus one and you can't get the dog off?'

One of the officers then yells at the bystanders to get back. 'Shut up and get back!' he said.

The same officer then escorts the K9 dog away while the other two rummage through the suspect's pockets.

'My own dog is better trained than that,' one of the bystanders, who appeared to be walking his dog, said.

The video has been viewed more than two million times on Facebook and has instigated debates about whether the police officers or the suspect was in the wrong.

One commenter said: 'The video begins during the middle of the incident but I'm pretty sure he resisted for the dog to attack him....stay out of trouble if you don't want to get bit by a dog.'

Another posted: 'Instead of helping save this man's arm the other officers are more worried with holding down his legs!

'That dog should be put down and that police department should be held responsible in civil court the same as any other pet owner!'

Blood gushes out of the man's arm while two officers arrive at the scene to hold his legs down