A minute-long video circulated online over the weekend has given Yu Jie, a deliveryman in Shanghai, notoriety for his timely and potentially lifesaving warning.

In the video, huge plumes of dark smoke can be seen rising in the distance as Yu, riding his scooter, shouts repeatedly to a crowd of onlookers lingering to watch the scene unfold on a bridge: "Hurry up, go away! Leave with your families!"

It was a scene in the city's Jinshan district after a fire broke out around 4 am on Saturday morning at Sinopec's petrochemical complex, which caused one death and one injury.

The fire was brought under control and flammable materials were allowed to burn off. The flames were finally extinguished on Sunday afternoon.

Although no further explosion occurred, Yu's calls for people to evacuate on the Ximen Xinqiao bridge, about two kilometers from the plant, won applause online.

The video had received more than 23,000 likes and 3,000 comments as of Monday.

One viewer named Chen Yijie commented: "You did a good job. It helped prevent possible injury if there was a second explosion. And it cleared the road for rescue vehicles."

A 35-year-old resident in Jinshan, Yu studied chemical engineering and technology at Shanghai Petrochemical Academy, and after graduation his first job was as a laboratory technician in another petrochemical plant.

Yu said he was at home when he heard the sound of an explosion, and went toward the direction of the smoke to check if there was any way he could help.

"When I neared the plant, I saw many people on the bridge. From my previous work experience, I knew it was very dangerous because a fire in a petrochemical plant could lead to continuous explosions," he said.

"And that's why I shouted at those onlookers and told them to find shelter quickly."

Some netizens, however, have called the videos an act of self-promotion because they were shot and published by Yu himself.

Yu dismissed the skeptics and said he only wanted to educate more people about the emergency response in such a scenario, and that the video was shot by a camera installed on his scooter helmet.

"What I did was without any ulterior motive," he said.

"I found happiness through helping others."