Christmas and New Year gatherings may have caused a bounce back in flu and other winter viruses, NHS leaders say.

Figures show that the average number of patients in hospital beds in England with flu last week hit 2,924 – a rise of 9% on the previous week. This comes after two weeks of decreasing numbers, prompting hope flu cases may have peaked.

NHS England medical director Prof Meghana Pandit said a combination of the vicious cold snap and winter viruses was making services “extremely busy”.

Hospitals are reporting the icy conditions have led to a rise in patients seeking help for injuries from slips and falls as well as struggling with respiratory conditions.

Pandit said: “It’s clear that the worst is far from over for the NHS this winter.”

Despite the pressures, there are signs the NHS is coping better than in the last few winters.

Ambulance delays when handing patients over to A&E staff were lower over the Christmas than the year before.

Health Secretary Wes Streeting said: “Today’s data shows we are not out of the woods yet.

“While the NHS is better prepared and performing more strongly than this time last year thanks to the tireless work of staff, the current cold snap is putting fresh pressure on frontline services.”

While flu cases have gone up, they are still well below the peak of last year which exceeded 5,000.

As well as flu, the number of patients in hospital with Covid and the vomiting bug norovirus have also increased.

Sarah Woolnough, of The King’s Fund health tank, said despite signs the NHS was coping better than in previous years the pressures being experience were still not sustainable and were not allowing service to provide the “best possible outcomes for patients”.

The warning comes as the Health Services Safety Investigations Body has warned that risky corridor care is becoming normalised in hospitals across the country.

The watchdog said patients being brought into A&E were being treated in waiting rooms, corridors and in ambulances outside hospital because of a lack of beds.

Dr Vicky Price, president of the Society for Acute Medicine, said there was a deepening crisis in emergency care.

She warned there were “people dying as a direct consequence” of the situation and called for immediate action to address the pressure.