A desperate search is underway to track down two missing babies in Melbourne.

One-year-old Ilham and one-week-old Daniel were last seen on Tuesday in Port Melbourne, sparking a public appeal.

'Police have concerns for the children’s welfare due to health concerns requiring immediate treatment,' a statement read.

'The children may be in the company of a family member but their whereabouts remain unknown.

'It is believed they may have been in the Richmond area on Wednesday evening.'

Victoria Police confirmed to the Daily Mail on Thursday afternoon that the children, who are related, are still missing.  

Anyone who sights the babies or has information about their whereabouts is urged to contact St Kilda Police Station or Crime Stoppers.