Melbourne siblings, 15 and 3, go missing

A three-year-old boy and his teenage sister have gone missing from Melbourne's north.

Paris, 15, and Corey Prince were last known to be at their home in Reservoir on Monday.

Police have been told the siblings are with a male family member but are concerned for the children's welfare given their age and the ability of the family member to care for them.

Despite searching a number of locations the children have not been found and anyone who sees them is urged to call triple-zero.

Paris has coloured hair and a slim build, while Corey has brown hair.