There has been a Covid-19 outbreak in St Gabriel's special school in Bishopstown, Cork.
It is believed that so far, there have been five positive cases recorded in the school.
Parents were informed of the first case on Friday. Another new case was confirmed on Tuesday. However, it is not believed that these two cases are connected.
The school has been shut since Wednesday.
It is understood all staff, students and anyone else who has come into contact with the children, such as bus drivers or SNAs, will be tested.
In a statement, the HSE said: "We do not comment on individual cases or outbreaks to protect the privacy and confidentiality of those involved.
"In any case where a case of Covid-19 is linked to an educational facility, Public Health professionals speak directly with the person, or family as appropriate, and asks them about their contacts.
"Public Health professionals also discuss the matter directly with the educational facility as part of that public health risk assessment.
"While we do not comment on individual outbreaks, the Department of Public Health can confirm that all appropriate procedures and precautions have been followed in relation to any cases notified in this region in recent days.
"Anyone deemed to be a close contact has been identified and contacted quickly."