A good Samaritan identified as Rajnish Thakur saved the life of a shopkeeper after locking horns with a sword-wielding attacker in Mumbai, India.

Video footage has emerged of the Indian man fighting a sword-wielding attacker to save the life of a helpless shopkeeper.

The incident happened on Tuesday night, when the attacker charged at Rajnish Thakur in his shop in Mumbai's Chembur neighbourhood.

Naseeruddin Mansuri, who was a customer in the shop, has been hailed a hero for rushing to defend Mr Thakur.

But Mr Mansuri was said to have reported that he now fears for his life.

He has asked journalists not to take photos of him.

"I have a wife and children. If some criminal recognises me from photo and comes after me, who will protect me? Please don't create any trouble for me," he pleaded.

Speaking about the incident, Mr Mansuri said: "For a moment, I couldn't understand what was happening. But then I managed to stop the attacker and also started shouting so more people gathered."

Mr Mansuri said he did not feel any fear. "At that time I had to just save this man... How could I watch someone being beaten up?"

After the video was shown on Indian television channels and posted online, Mr Mansuri was hailed as a hero on social media.

But, he says he has received threats and is worried about his family and has not left home since after the incident.

Police have arrested the attacker and named him as Akram Sheikh.

Reports say Mr Thakur was attacked because he has been actively campaigning against extortion by the underworld.