Why two small children were kidnapped in broad daylight from their Melbourne home in their parents' Mercedes is still a mystery, but police do not think it was a random attack.
The three-year-old boy and five-year-old girl we found at a second house while approaching the stolen car shortly before 7.30pm on Monday, after being taken from their Blackburn North home that morning.
The children's 32-year-old mother was assaulted, bound and gagged. Her 34-year-old husband, the children's father, was at work.
Police are still interviewing three men and a woman and have had to source Cantonese interpreters to properly talk to the children's mother, who was taken to hospital following her assault.
"There (are) a lot of unanswered questions in this investigation, it's still quite raw and very early on in the investigation," Victoria Police Commander Mick Frewen told reporters on Tuesday.
Cmdr Frewen said there is no known relationship between the victims and those arrested, however "I don't think it was random and I don't think the community needs to be concerned."
The children were taken from their home while wearing pyjamas by an armed man who entered the Blackburn North between 8am and 8.30am on Monday.
Police put the call out for information within hours.
Cmdr Frewen said the children "have displayed, resilience, well beyond the years and they're quite upbeat" despite their ordeal.
He could not say if or when the four people in custody would be charged or appear in court.
