The man, aged 50 and from Malmö, appeared in Malmö District Court to face charges of child rape over his attacks on two girls under 15. A further two attacks on girls over 15 have led to charges of sexual assault.
"There could be more victims. We don't yet know," said prosecutor Thorbjörn Sjöberg.
The attacks took place in the man's apartment between late autumn last year and his arrest at the end of December.
"The girls have come into contact with him by various means, but it does not appear that it was over the internet," said Sjöberg.