A home helper in Ho Chi Minh City brutally assaulted seven members of his boss' family with a hammer on Sunday before trying to kill himself with it.
Police are investigating the apparaently unprovoked, irrational act of violence on the family of Le Cong Quang, 39, who runs an advertising firm.
Among the victims were Quang's wife, his 13-month-old son and his niece, a 19-year-old college student who was visiting the family, local news website VietNamNet said.
Eyewitnesses said they saw Duong Van Nuoi, 30, carry a hammer around 0.3 meters long covered with blood after hearing shouts and cries from the office-cum-residence of advertising firm Huong Sinh.
The attack took place at six in the morning when most of the victims were asleep.
Huynh Hoai Nhan, a 17-year-old worker of the firm, said he survived as he managed to hide behind a door.
Nhan said Nuoi hammered the company's owner unconscious and other members of his family were severely injured.
"I still don't know what made him act that brutally," Nhan told the police.
According to workers of the company, Nuoi was on good terms with the family. He had also gone to a café with the family the previous night.
The injured have been admitted at the Cho Ray Hospital. Three of them, Quang, his wife Phan Thi Hong Chi and his niece Le Thuy Ngan, needed emergency surgery, doctors said.
HCMC police have arrested Nuoi for further investigation. He was also injured as hammering his own head after attacking everyone.
Nuoi has been with the family for two months.