Four 20-somethings were arrested for imprisoning and torturing two people in their early 20s, Busan Gangseo Police said Tuesday.

The group, demanding 2.6 million won ($2,300) from the victims for providing them a month’s accommodation, locked up the 25-year-old sister and 23-year-old brother, pulled off nine of their toe nails, beat them with clubs and burned them with lit cigarettes, police said.

They took turns guarding the victims to stop them escaping. 

The brother escaped by telling his captors that he was going to retrieve some money he had stashed away in a secret spot. He alerted the police, leading to the rescue of his sister.

The police said the group began by occasionally beating the siblings, but when the victims did not fight back, began to increase the severity of their abuse.

One of the arrested men was the female victim’s boyfriend.

The victims had gone to stay with him after leaving their parents’ home, but when the boyfriend, who was unemployed, was evicted for failing to pay his rent, the three of them went to stay with his acquaintance.

The acquaintance was living with his girlfriend and a female friend, who together make up the remaining three suspects. The boyfriend had allegedly most actively tortured the victims.

The case will be passed to the prosecution as early as Wednesday.

(kaylalim@heraldcorp.com)