The HSE has confirmed that 21 residents at a single nursing home in Dublin have died from the coronavirus in a three-week period since April 2.
St Mary's Hospital in the Phoenix Park is a state-run nursing home that cares for almost 200 elderly residents.
The HSE said that 11 residents died at the home between April 2 and April 17 after contracting the virus. A further 10 residents died in the following week between April 18 and April 25.
All 21 residents tested positive for COVID-19.
Minister for Health Simon Harris offered his condolences to the residents and their families in a statement on Saturday night.
"In such a short space of time for so many residents to have passed away." he said. "I can’t imagine how traumatic that is."
Harris paid tribute to all healthcare workers who were continuing to work against "a huge backdrop of personal tragedy."
The HSE also issued a statement on Saturday night expressing sympathies to the loved ones of those who died at the nursing home.
Read more: Ireland has let down its elderly in the COVID-19 fight
The HSE said: "We offer our deepest sympathies to their family and friends and our thoughts are with them at this difficult time.
"St Mary’s Hospital maintain regular contact with families and relatives at all times and this has increased significantly since the onset of changes to visiting arrangements and the first suspected case of COVID-19."
A number of staff members and residents at the nursing home have also tested positive for the coronavirus, according to the HSE. The HSE said that the figure was changing daily and did not disclose an exact number of cases.
Large-scale testing of residents and staff members at St. Mary's Hospital is currently ongoing in a bid to prevent further spread of the virus and the home is being supplied with PPE on a daily basis.
Harris said that 284 nursing homes around the country were receiving PPE from the HSE.
Around 120 HSE staff have been deployed to nursing homes, according to Harris, and he said that home help workers could be redirected to the nursing home sector to bolster staff numbers.
The outbreak of COVID-19 in nursing homes across Ireland has proved to be one of the most worrying issues of the pandemic.
Ireland's Chief Medical Officer Tony Holohan confirmed Thursday that 361 nursing home residents had died from COVID-19 or 45% of the country's death toll as of April 23.
Read more: COVID-19 “catastrophe” as one third of Ireland’s nursing homes test positive