Man In Custody After 'Burning Three With Flamethrower Made From Cockroach Spray'

A man was detained in hospital on Monday night after allegedly burning three people with a makeshift flamethrower in Western Australia.

It's alleged the Kalgoorlie-Boulder man torched the victims, who were known to each other, at a house on Sunday with a flamethrower fashioned out of cockroach spray and a lighter.

WA police said a 22-year-old woman suffered extensive burns to her arms, back and neck as a result of the incident.

Two male victims in their late 20s and early 30s also sustained burns to their neck, ears, arms, and hands, police said.

South Korean national Jinwoo Yeo has been charged with three counts of an unlawful act with the intent to harm.

The 31-year-old was due to appear in court on Monday but was instead made an involuntary patient and detained at Kalgoorlie Health Campus.

Local police told Kalgoorlie Miner the man was sedated with ketamine and may need a translator.

Yeo will appear in Kalgoorlie Magistrates Court via video link later this month.