A kindergarten teacher accused of burning seven children with a hot iron on last Tuesday has been detained by police for 10 days and fired from her job in East China's Jiangsu province, local authorities said over the weekend.

The 30-year-old teacher, surnamed Yi, who worked at Xinghua city's Banqiao Kindergarten, said she "did not know the iron was still hot when she used it to discipline the children", according to a news conference organized by the city government on Saturday.

The seven children were burned on the face. As of Saturday, two children had returned to class, one had dropped out of the kindergarten, two were resting at home and two were seeking treatment in Shanghai, the city government said.

A medical worker surnamed Zhang from Shanghai Ruijin Hospital said on Sunday the two children, who had come to Shanghai with their parents, had returned home after they were treated.

Zhang said the children suffered deep second-degree burns and will return to the hospital for checkups a week later.

It will take about three weeks for the outer skin to heal and an additional six to 24 months for the scar to disappear, the doctor said. However, there is a possibility of permanent scarring.

It was also announced at Saturday's news conference that Xinghua police detained Yi for 10 days and fined her 500 yuan ($75).

The kindergarten's owner apologized at the news conference and said Yi had been fired.

Many people are skeptical of Yi's claims that she did not know the iron was still hot. A typical online post about the incident read: "How could you think the iron isn't hot, since you burned seven kids with it?"

Police said they believe Yi did not foresee her actions' consequences.

Dai Yongjian, with the city's public security bureau, said Yi's coworkers said that the iron had been unplugged for more than 10 minutes before it was used to burn the children.

"Yi had treated children well before the incident, according to our talks with the kindergarten's owners and teachers, and the children's parents," Dai said. He added that the students' faces did not show any injuries until that afternoon.

Yang Qiuhong, mother of Wang Junhua, who was injured in the incident, said, "I was angry at first but have since forgiven Yi and the kindergarten. Yi used to treat my child well. And after the incident, the kindergarten's headmaster rushed to my home and took my daughter to the hospital."

The police said they believed Yi lacked necessary medical knowledge and did not seek treatment for the children after their faces began to show signs of being burned.

Deputy chief of the city's education bureau Wu Gang said Yi "very deeply regretted her actions".

Yi does not have a preschool teaching certificate. About 60 percent of the city's 1,600 kindergarten teachers do not, Wu said.

Jiangsu provincial government regulations require the certificates for some kindergarten posts, including those of schoolmasters and medical workers. Others are required to earn the certificate within three years of starting at a kindergarten.

Banqiao Kindergarten is a private school established in 2000. It is popular among parents, who join long lines to enroll their children, Wu said.