London, Dec 3 (IANS): The number of Covid-19 cases in the UK has again increased above one million, in a worrying sign of a new winter wave, according to the Office for National Statistics (ONS).

The number of people in the UK testing positive for the virus rose by 6 per cent in the week to November 21 -- up from 972,400 for the previous seven-day period, Xinhua news agency quoted the ONS as saying on Friday.

It is the first increase in nationwide infections since the week ending October 17.

There has been a 40 per cent jump in the number of patients in hospital with flu compared to the previous week, according to weekly figures from Britain's National Health Service (NHS).

This follows a warning from clinical leaders that the NHS is facing the threat of a "tripledemic" of Covid-19, flu and record demand on urgent and emergency services.

Hospital admission rates and intensive care admission rates have increased further in the last week, the UK Health Security Agency (UKHSA) said.

"As we head into the coldest part of the year, we would expect to see the prevalence of Covid-19 and other winter viruses begin to increase as people mix more indoors," Mary Ramsay, director of Public Health Programs at UKHSA, said in a statement.

"While Covid-19 and flu can be mild infections for many, we must not forget that they can cause severe illness or even death for those most vulnerable in our communities."

Since the onset of the pandemic in early 2020, the UK has so far recorded a total of 24,024,746 Covid-19 cases and 197,253 deaths.