Authorities are assessing the mental state of a man who allegedly injured 16 children and a teacher with a knife Wednesday at a primary school in south China's Guangdong Province.

The suspect, Chen Kangbing, a 33-year-old art teacher in Leizhou City, showed an inability to answer questions clearly, said Li Changwu, secretary of the Leizhou City Committee of the Communist Party of China.

Chen was receiving a comprehensive psychiatric examination from the Zhanjiang City Public Security Bureau, Li said.

Police detained Chen an hour after he was alleged to have launched his attack at Leicheng First Primary School in Leizhou at around 3 p.m..

Chen worked at a different school.

He sneaked into the campus with a crowd of teachers from different schools to attend an "open class" where they would observe teaching methods at the school, said Chen Riwen, a spokesman with the provincial education department.

The victims, who suffered wounds to their heads, backs and arms, were rushed to Leizhou People's Hospital, said Mo Dechun, head of the hospital's surgical department.

Five children were seriously injured, but all the injured were stable, Mo said.

The 16 students were fourth or fifth graders, one of whom tumbled and hurt himself when he tried to escape, he said.

"I hid under the table in the classroom when he struck the knife at my head. I didn't feel any pain at the time," injured student Xiao Huang told Xinhua.

Xiao said the teacher blocked Chen and shouted "Run, Run!" to the students in the classroom.

Xiao Wen, 12, one of the seriously injured, was receiving a blood transfusion and was breathing with oxygen at midnight.

She received cerebral injuries and suffered heavy blood loss, Xiao Wen's father told Xinhua.

Initial investigations showed that Chen Kangbing was a teacher at Hongguan Primary School, in Baisha town, Leizhou city.

He had been on sick leave since February 2006, Chen Riwen said.

After the rampage, teachers of the primary school surrounded Chen to keep him from fleeing or hurting more people before the police came, witnesses said.

The school resumed classes Thursday, Chen Riwen said.

Police are still investigating the case. The attack occurred just hours after Zheng Minsheng, who stabbed eight pupils to death and seriously injured five others, was executed in neighboring Fujian Province.