A student who was injured in a violent assault by a man who slashed and injured 11 passers-by after killing two of his relatives in Shanghai, receives treatment at Fengxian Central Hospital on Wednesday. XU CHENG / FOR CHINA DAILY

Eleven people injured in violence that also left two others dead on Wednesday in suburban Shanghai remained hospitalized on Thursday, as witnesses praised those who subdued the knife-wielding assailant.

Ai Kaixing, president of Fengxian Central Hospital, said that most of the injured - including six children, 8 to 10 years old - were wounded on their heads by the assailant, who slashed the victims with two knives.

The hospital brought in orthopedists and neurosurgeons to treat the victims, Ai said. None of the injuries is considered life-threatening.

The city's education commission demanded that all kindergartens and primary and middle schools improve their campus security.

The commission alerted the institutions to increase security forces to guard the school gates and said the gates must be shut while students are in class.

Police said the investigation is continuing, and a test has yet to be done on the suspect's mental condition.

The assailant, identified by police only as Zang, started to slash randomly at passers-by at the gates of a primary school in Fengxian district on Wednesday after he is believed to have killed two women during a family dispute.

Zang, 37, had an argument with his sister and her mother-in-law in the women's apartment just before slaying the pair and going on a rampage, witnesses said.

A neighbor of the women who gave his name as Xia said Zang had asked his sister if he could borrow money to buy an apartment, but she refused. The three then argued.

Zang arrived in Shanghai on Tuesday from neighboring Jiangsu province, police said.

Police said he then jumped into a busy street in the district's Jinhui township and began slashing people randomly, police said. He quickly shifted his attention to children who had been walking from the campus of nearby Jinhui Primary School.