An 18-year-old is understood to have become the youngest person to die in the UK after testing positive for coronavirus.
The number of people who have died after contracting the highly contagious respiratory disease rose by 48 in a day to 281 on Sunday.
COVID-19 infections in the UK have increased by 635 to 5,683, the Department of Health said.
In England, 37 more people who tested positive for COVID-19 have died, bringing the total number of confirmed deaths to 257.
The patients were aged between 18 and 102 years old - thought to be the youngest and oldest so far.
They were all were in vulnerable groups, with underlying health conditions.
Boris Johnson said in his daily news conference on Sunday that the government is ready to impose tougher restrictions to curb the spread of coronavirus if people do not follow the guidance on social distancing.
There have been seven fatalities in Wales over the last 24 hours, taking its total to 12 and a further three in Scotland, where the number of deaths overall now stands at 10.
Meanwhile, an elderly patient with an underlying medical condition has become the second person to die in Northern Ireland after testing positive for coronavirus.
Health officials said another 71 people had tested positive for coronavirus in Wales, bringing the total number of confirmed cases to 347.
In Scotland, 416 have now tested positive.
Coronavirus: 18-year-old 'youngest' to die in UK as fatalities rise by 48 to 281
The number of COVID-19 infections has risen by 665 in a day to 5,683, the Department of Health said.
news.sky.com