HELSINKI (AP) — Finnish police have arrested a 35-year-old woman on suspicion of manslaughter after finding five dead babies in an apartment building, Detective Superintendent Seppo Leinonen said Wednesday.

Officers found the bodies in “badly smelly packages” Tuesday in a basement cupboard of an apartment building in the western city of Oulu after they were alerted to the scene by emergency services.

“A woman arrived there as officers had begun their investigation, saying she had put the packages into the cupboard,” Leinonen told the AP. “She said she’d given birth to the stillborn babies between five and 10 years ago at home.”

Leinonen said the woman could not give a clear motive for keeping and storing what he said appeared to be fetuses for so long.

He declined to identify her except to say that she was a local Finnish woman, married with children, who had moved into an apartment in the building in Oulu, some 500 miles north of Helsinki, a few months earlier. He said no other family members were suspected of being involved.

Leinonen said police are treating the case as suspected manslaughter. He declined to give more details, saying the forensic examination is expected to take months.