HASKELL, N.J. (CBSNewYork) — The New Jersey Department of Health announced Tuesday that six children died as a result of an outbreak of adenovirus at the Wanaque Center for Nursing and Rehabilitation.

The health department had earlier confirmed 18 cases of the virus.

“Adenoviruses are a family of viruses that often cause mild illness, particularly in young children,” Department of Health director of communications Donna Leusner told CBS 2. “Unfortunately, the particular strain of adenovirus in this outbreak is affecting medically fragile children with severely compromised immune systems. The strain has been particularly associated with disease in communal living arrangements and can be more severe.”

The Passaic County facility has been instructed to not admit any new patients until the outbreak ends.

An inspection team dispatched to the facility on Sunday found minor hand-washing deficiencies, the health department said. A team was sent back Tuesday.

The facility treats children with already compromised immune systems. Doctors say the general public is not in danger.

The outbreak investigation is ongoing.