Three coronavirus-linked deaths were registered in Northern Ireland last week, official figures show.
It said the virus had featured on the death certificates of 876 people in total by 4 September.
The Department of Health's daily figure for the same date was 564 - more than 300 fewer.
Its statistics are based on a patient having previously tested positive for the virus.
Nisra said there have been 466 deaths in hospital (53.1%) - 81 of those people were normally resident in care homes.
Taking that figure, and the 351 who died in care homes, it means care home residents account for half of all Covid-19-related deaths in Northern Ireland.
In the week up to last Friday, no Covid-19 related deaths occurred in a care home.
Eight people have died in hospices (0.9%) and 52 at residential addresses or other locations (6%).
People aged 75 and over account for 80% of all Covid-19-related deaths.
In the week ending 4 September, the percentage of all Covid-19 related male deaths was 49.9% and female deaths 50.1%.
Those with an address in the Belfast council area account for 249 of the 876 deaths registered by last Friday. Fermanagh and Omagh has recorded the fewest (17).
The provisional number of all deaths between 29 August and 4 September was 234 - 69 fewer than in the previous week (303) and 21 fewer than the five-year average (255).
That five-year death rate is used to compare the number of weekly deaths that would normally be recorded at this time of year.
The measure captures all deaths linked to coronavirus - those involving confirmed infections, which feature in the health department's daily figures, as well as the suspected cases in which coronavirus is mentioned on the death certificate.
Nisra also recorded the number of "excess deaths" registered in the past 23 weeks as 1,121.