Johannesburg - A man has been arrested after he held three people hostage in Randburg, using two Swiss army knives, Gauteng police said on Wednesday."The perpetrator is a tenant in a cottage on the property… He held three people hostage: the owner, his wife and someone alleged to be the ex-girlfriend of the perpetrator," said police spokesperson Captain Mavela Masonda.The man allegedly used two small Swiss army knives to keep the people captive.Police were called to the scene at 09:00 after the owner's daughter received an SMS from her mother to alert the police.Soon, police hostage negotiators began talks with the hostage-taker."We cannot confirm what was the motive…. What we were negotiating with him was to release the hostages," said Masonda.The hostage-taker’s alleged ex-girlfriend was the first to be released, at approximately noon."An hour later, he released the wife."Masonda said the owner of the property was released at about 14:00. All the hostages were unharmed, but were treated for shock by paramedics on the scene.Just before 16:00, the hostage-taker handed himself over."We suspect that he took some tablets. He was taken to hospital in an ambulance under police guard."The man was in stable condition. He was facing charges of kidnapping and the possession of dangerous weapons, said Masonda.