Witnesses have described the moment on Wednesday when a knife-wielding man went on the rampage in a bustling Shanghai street.

The attack, which injured 11 people, including six children, came shortly after the suspect is believed to have killed two women over a family dispute.

People at the scene said the man, who was carrying two knives, entered the street in Fengxian district's Jinhui township at about 4 pm and began slashing randomly at passers-by.

"People didn't realize what was going on at first," said Wang Tongyong, a locksmith who has a stall nearby. "We thought it was a traffic accident."

Others recalled the man quickly began to target the children who had been walking from the campus of nearby Jinhui Primary School.

Once the crowd understood what was happening, Wang said people grabbed whatever they could find on the ground to fight off the attacker.

To escape, some of the children and their parents fled toward the school, said the father of a first-grader who gave only his surname, Li.

"When I arrived at the school, children were hiding everywhere. They were terrified," he said. "You dare not look into their eyes. You'd be horrified by the fear that was in those children's eyes."

He said that the school's two security guards, in their 40s and 50s, failed to protect the youngsters.

"One was stood close to my wife, but he didn't make a move," he added.

Wang said the crowd in the street was eventually able to subdue the attacker and hold him until police arrived.

The suspect, identified by police only as Zang, in his 40s, is also accused of slaying his sister and her mother-in-law in the women's apartment just before the rampage, police said.

A neighbor of the women who gave his name only as Xia said Zang had asked his sister to borrow money to buy an apartment, but his request was refused. The trio had then argued.

Zang, who arrived in Shanghai on Tuesday from neighboring Jiangsu province, according to the police, is then believed to have killed both women.

On Wednesday night, some residents complained that police officers were too slow in arriving on the scene, despite a police station just around the corner.

All 11 victims are being treated at a hospital in Fengxian and are being guarded by police officers. None of the injuries were thought to be life-threatening.

Police say investigations are continuing.

wangzhenghua@chinadaily.com.cn