The HSE is investigating the deaths of six elderly patients at a nursing home in Buncrana..
The victims are believed to have had a respiratory type illness at the private facility. The deaths happened over an 11 day period, five of them in five days .
The HSE says all residents are receiving either active or preventative treatment.
Representitives of the Health Information and Quality Authority are visiting the facility tonight and tomorrow.
The HSE says a full investigation is underway, and all appropriate treatment and control measures have been put in place.
North West Director of Public Health Dr Peter Wright, says health authorities are closely managing and monitoring the situation.
Blood samples from the patients have been sent to the National Viral Reference Laboratory for determination as part of the investigation.
The HSE has also requested that GPs report unusual clusters of respiratory illness.
In a joint statement tonight, Health Minister Dr James Reilly and Junior Minister Kathleen Lynch, express sympathy with the bereaved and say they are liaising closely with the HSE.
In addition to the actions being taken by the HSE, Minister Reilly says he has discussed the matter with HIQA.
On foot of that conversation, HIQA will now visit the home tonight and tomorrow to ensure that all action is taken in the best interests of the care and welfare of the residents and staff.