BEIJING – Parents across China this week were shocked when two separate stories of gross physical abuse against kindergarten-aged children made national headlines.

On Tuesday, police in the city of Taiyuan, the provincial capital of Shanxi, detained a teacher at the Sky Montessori kindergarten after parents complained about alleged physical abuse there.

Closed-circuit TV video from inside the classroom -- released to the media soon after the scandal broke -- confirmed what parents had already inferred from their children's bruises and stories: that their teacher, Li Zhuqing, was slapping, kicking, hitting and verbally abusing them.

A video from a local Shanxi provincial news program (report in Chinese; footage starts around 34 seconds in) shows Li repeatedly slapping and shoving around the children over a 10 minute period. Two girls are shown being repeatedly slapped in the face while a boy is seen being slapped and then shoved into another student.

The father of one of the girls said he reported the abuse to the police after his daughter came home with a bruised eye and cheek, and explained to the news program why his daughter was singled out.

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"The teacher [Li] did it because she couldn't answer 10 plus one correctly," said the father, surnamed Han. He noted that his daughter could do simple single-digit addition, but could not understand Li's explanation of how to solve higher sums.

According to Han, his daughter was slapped in the face around 70 times and kicked twice, while three other children in the class were reportedly hit 43, 10 and 27 times respectively.

"She is not a teacher. She should not be a teacher. To put it plainly, she is not a human being," said Han.

The story quickly went viral and drew hundreds of thousands of comments on China's Twitter-like service Weibo.

"How can the world have people like this? Her parents should be ashamed of having a daughter like that!" wrote one user. "Watching this video made me cry ... Children should never be treated like this," added another.

Li was detained under a 15-day "administrative detention," common when Chinese police are waiting to charge someone, Chinese state media reported. The Montessori school, which reportedly was unlicensed and therefore operating illegally, was also shut down indefinitely. Taiyuan city authorities pledged a month-long investigation of other municipal schools to ensure there were no other cases of abuse. 

Boy held up by ears
But there was more outrage to come: Another school abuse scandal broke the next day after a picture taken at the Blue Peacock kindergarten in Wenling, Zhejiang province, circulated online.

The photo showed a teacher holding up a child by his ears -- the boy obviously in pain and the teacher grinning widely.

The teacher, Yan Yanhong, 20, was detained and police opened an investigation. Authorities revealed that she had been working without a license and that the school had been applying to certify her while she worked.

News of the abuse quickly spread around the Web, where it garnered more than 4 million posts and became a trending topic on Weibo by Thursday.

"This person is seriously sick!" wrote a disgusted Weibo user. "My child starts school next year, how frightening!" said another.

Teng Linhua, Vice-director of the Wenling Education Bureau, told the China Daily newspaper that "all teachers at private and public schools must have qualifications before being hired."

Teng said only 40 percent of kindergarten teachers in Wenling were properly qualified.

NBC News' Le Li and Johanna Armstrong contributed to this report.