Police in Singapore are investigating the assault of an elderly man after he patted a young girl on the head at a food court.

A man believed to be the father of the young girl, who appeared agitated after the gesture, allegedly threw the 73-year-old to the ground.

Security camera footage of the incident on Saturday went viral over the weekend, with many voicing anger at the younger man's reaction.

In a statement on Sunday night, police said they had identified a 40-year-old man involved in the incident.

The police urged people "not to speculate on the incident or its circumstances" and let police "conduct investigations and establish the facts of the case".

A video of the incident shows the elderly man patting the child on the head as he walked past her table at a food court in a shopping centre.

A woman seated at the same table, believed to be the girl's mother, immediately stopped him. Another man believed to be the father,walking back to the table, confronted the elderly man.

After what appeared to be a heated exchange, the younger man was seen grabbing the elderly man's arm and throwing him to the ground.

The video quickly went viral in Singapore, sparking widespread condemnation of the younger man's actions. While some argued the elderly man should not have touched the child without the parents' consent, most agreed the physical altercation was an overreaction to a pat on the head.

The clip was published on the social media pages of Bei-Ing Wanton Noodle, a stall at the food court.

The post was written by someone who identified himself as the son of the elderly man, and it sought help to identify the alleged assailant.

The post said the elderly man was "in his 70s and has previous leg and hip injuries", but "did not want to pursue the matter further".

"Afterwards, the man sat down with my father, apologised and offered him a drink," the post said.

"While we appreciate that he eventually apologised, my father is now suffering from severe back pain following the incident. A drink and an apology cannot simply take away the physical pain or injuries he is experiencing."

The elderly man told local outlet Channel News Asia that he had patted the little girl's head because she "was very adorable".

"Old people like to pat young children's heads," he said.

He added that he started hurting hours after the fall, and that he was taking Panadol for his pain.

In another post, the elderly man's son thanked the police for responding to the matter quickly, adding they "sincerely hope that justice will be served for my father".