No less than eight babies and toddlers at a Tokyo care centre have tested positive for the coronavirus.
They contracted the virus after a staff member contracted the disease, its operator said on Wednesday.
According to the Agence France Presse, AFP, Tokyo Saiseikai Central Hospital, which operates the facility, said the affected children had been hospitalised, while another 21 tested negative and were under observation.
The facility is for orphans or children separated from their parents because of possible abuse or neglect.
A staff member tested positive for the virus on April 16, prompting tests for all the children, the hospital said in a brief statement, without disclosing further details.
Tests are being carried out on 46 staff members who are self-isolating at home.
The children who tested positive were not experiencing high fever, local media said.
Japan has so far avoided a huge spread of coronavirus infections, but some medical facilities have suffered in-hospital transmissions.