Eight people, one of them a tourist from Yogyakarta, were injured when a man ran amok with a Samurai sword outside a hotel on Jl Pantai, Kuta.
They were treated at Sanglah Hospital in Denpasar.
Kuta Police chief Wimboko said the attacker, Putu Eka, son of the hotel owner, was detained and beaten by local people before being handed over to police. He was taken to Bangli Psychiatric Hospital.
His family apologised for the rampage, last Friday, and offered to pay for the hospital treatment of the victims. They said Putu was mentally ill but had never hurt anyone before.