Many people gathered on a street near Shanghai World Foreign Language Primary School on Thursday evening to mourn those killed in a knife attack there earlier in the day.

Three male students and one female parent were attacked by a man with a kitchen knife at around 11:30 am while walking on the street near Shanghai World Foreign Language Primary School, the victims’ school, local police said. Two students died, while another and the parent are in stable condition.

Videos shot on scene by witnesses immediately after the assault have been circulated online ever since, along with descriptions from self-claimed witnesses to the attack. It is said the perpetrator bought the knife from a nearby supermarket and aimed directly at the students’ necks for attack.

Some said he even stopped to smoke a cigarette after the attack before he was arrested by local police.

The attacker, surnamed Huang, is 29 years old and unemployed. He said he is hopeless and did this for revenge.

Thursday is the day when the students of Shanghai World Foreign Language Primary School, located on Pubei Road, Xuhui district, returned to school to review their final exam papers. The semester ends Friday.