A vehicle plowed into students and pedestrians outside a primary school in China's Hunan province on Tuesday morning and several people were injured, state media said, as worries spread over a spate of violent attacks in the country over the past week.

CCTV and other state media reported the vehicle hit people outside the Yongan Primary school in Changde city as students were coming in for the day.

Many were injured in the incident, CCTV reported. A more detailed tally of the injuries was not available, and it was not immediately clear what had caused the crash or whether it was intentional.

Reuters was unable to connect by phone to emergency services for Changde to seek comment.

The incident happened days after a driver rammed his car into a crowd at a sports centre in Zhuhai in southern China, killing 35 people and severely injuring 43 in one of worst public attacks in recent memory.

Short video clips circulating on Chinese social media on Tuesday showed young children running near the school, some into the school compound, and shouting, "Save us." Someone can be heard shouting, "Call the police."

In another video, a man is surrounded by a crowd and apparently beaten with sticks and rods. A separate clip shows a man handcuffed and being held down on wet cement by a figure in uniform.

Reuters was able to verify the location of the videos matched the details of the crash reported by Chinese state media at a primary school for children between about 6 and 12 years old.

CCTV reported that the driver of the car that had crashed into people near the school was not the parent of a student there.

"Why are such incidents happening more and more frequently lately, hit-and-runs, and always involving students? What has happened to society now?," said one commentator on social media platform Weibo.

Police blamed last week's Zhuhai deaths on a male driver angry at his divorce settlement.

Days later, a former student went on a stabbing rampage at a vocational college in eastern China's Wuxi, killing eight people.

In both the Zhuhai and Wuxi cases, little information has been released by police, though from brief statements made public, it appears the two men lashed out with fatal violence against unrelated bystanders after suffering an economic loss.

The lack of details released about these and similar attacks reported this year have stirred discussion on Chinese social media, much of it quickly censored, about a rise in economic and societal pressure in the country and the mental health resources available to deal with it.

Qu Weiguo, a Fudan University professor, said the recent cases of "indiscriminate revenge against society" in China had some common features: disadvantaged suspects, many with mental health issues, who believed that they had been treated unfairly and who felt they had no other way to be heard.

"It is important to establish a social safety net and a psychological counselling mechanism, but in order to minimise such cases, the most effective way is to open public channels that can monitor and expose the use of power," Qu posted on the Chinese social media platform Weibo.

The short essay was removed by censors on Sunday afternoon.