The case of a mother who confessed last month to killing her two newborns and storing their bodies in her refrigerator has become a precursor to a disturbingly growing list of infant deaths as the government continues to investigate babies unregistered in the state system.

The National Office of Investigation(NOI) under the National Police Agency said on Thursday that as of 2 p.m. Wednesday, 598 out of 664 submitted cases of unregistered babies are being looked into.

In just one day, the number of cases jumped by 198 from the 400 submitted at the same time on Tuesday, with eight more deaths confirmed to bring the total to 23.

The tally climbs to 24 when counting a new case that was confirmed earlier on Thursday in Yongin, Gyeonggi Province, where police arrested a man suspected of killing his newborn son in March 2015 and burying the baby’s body.

Also on Thursday, Incheon Metropolitan Police arrested a woman in her 40s for allegedly burying her newborn daughter in a garden without a proper funeral following the baby’s death the day after she was born in August 2016.

Currently, the Gyeonggi Nambu Provincial Police Agency is carrying out criminal investigations into ten cases and has closed eleven cases without charges.

The woman accused of killing her two newborns in Suwon, Gyeonggi Province has been referred to the prosecution in a case stemming from an audit by the Board of Audit and Inspection of babies with medical records from birth that were not registered in the state system.