Northern Ireland is "on a knife edge" in efforts to suppress the coronavirus peak, a top Stormont scientist has warned.
Professor Ian Young, the chief scientific adviser to the Department of Health, said a slight slippage in public adherence to social distancing measures could be the difference between the death rate falling or continuing to rise.
His comments came as the region recorded its highest daily death toll in the outbreak to date.
The deaths of 18 people with Covid-19 in Northern Ireland hospitals brought the total in the pandemic to 158.
Health Minister Robin Swann said the figures should serve as a "grim wake-up call" to anyone who was becoming complacent.
Last night a further 43 deaths were confirmed in the Republic as it, too, reported its highest daily toll yet.
Across the island of Ireland, 644 people are now known to have died from the virus.
At the daily Covid-19 press briefing at Stormont, the minister addressed concerns about the inability of family members to be with their loved ones in their final moments.
Mr Swann said advice from clinicians indicated that allowing visitor access to intensive care units presented "too significant a risk".
However, he said he had requested the Northern Ireland Critical Care Network to review the issue.
Prof Young said modelling analysis suggested Northern Ireland was either at or very close to the peak of the first wave of the infection.
He said the fact it had not been as bad as some earlier models had suggested was down to the high level of public adherence to social distancing rules.
"It is possible that we might continue to see a rise in deaths for another week or so," he said.
"And today's very sad news in terms of deaths and bereaved families is in keeping with that.
"The fact that we have reached the peak now and that it is perhaps not as bad as previously anticipated is a tribute to the relatively high degree of adherence on the part of all of the public to the social distancing measures which are in place.
"Nonetheless, I need to stress that this is very much on a knife edge at present. It's absolutely vital that people continue to adhere strictly to the measures which are currently in place; even a relatively small departure from that would be enough for us to see an increase in Covid again.
"It's very important that we suppress this wave one of the epidemic as much as possible in order to allow us to move forward and make decisions about how best to respond to the next wave."
The scientist said ministers faced some very difficult decisions on how to manage social distancing restrictions until a point that sufficient immunity existed within the population.
He said relaxing measures around the shielding of older people and those in high-risk groups would present the "highest risk".
"Any decision to relax shielding would come with the highest risk in terms of pressure on the health and social care system and also the highest risk for the individuals who are currently shielded," he said.
Mr Swann extended his condolences to the latest families bereaved by the virus.
"Today's report should be a grim wake-up call to anyone who is getting complacent about what we are going through," he said.
The minister said there were currently 45 patients with Covid-19 in ICU beds in Northern Ireland and there were 105 new hospital admissions in the region on Wednesday - the largest number of the week.
"We are in the midst of the biggest public health crisis in the history of Northern Ireland," Mr Swann said.
"We are living through scenes that only three months ago would be wholly unimaginable. We must realise that we are in the fight against this virus for the long haul."
Across the UK, the number of coronavirus patients who have died in UK hospitals has gone past 13,000 after another 861 deaths.
The Department of Health announced the increase, which takes the total to 13,729.
It comes after England's Chief Medical Officer, Professor Chris Whitty, warned of a spike in deaths due to a probable lag in reporting over Easter weekend, following four consecutive days of sub-800 increases.