What exactly happened to the family is still unclear. According to Turkish media, the children, boys aged 15 and 17, would have become ill after they had eaten on Taksimplein in Istanbul. Hotel staff found the boys died in their room on Friday morning.
Shortly thereafter, their father was also unwell and admitted to the hospital, where he is still being treated.
The family comes from a village in Noord-Holland. Because of the traceability, the ministry does not want to say what place it is. Family members of the victims are taken care of in Istanbul.