The number of people suffering from flu in England is rising, according to official figures released on Thursday.

However, the number of cases is not yet at epidemic levels.

Figures from the Royal College of General Practitioners show 124 people per 100,000 in England were suffering from the bug in the week ending on Boxing Day December 26.

The week before 109 people per 100,000 had flu, compared with 68 per 100,000 in the week ending December 19.

A spokesman for the Public Health Laboratory Service, which collates the figures, said epidemic level was above 400 per 100,000.

A rate of between 50 and 200 per 100,000 was normal for this time of year, while 200 to 400 would be higher than normal.

Central England worst hit

Pople in the central area of England were suffering more than other areas, with 145 cases of flu per 100,000.

In the south there were 124 cases per 100,000 and in the north just 80 cases per 100,000.

The spokesman said: "There is an increase but the number of cases is still within the band of normal seasonal activity."

The increase in cases probably accounts for the inundation of a National Health Service 24-hour advice line during the Christmas period.

A total of 60,000 people contacted nurses on the NHS Direct system between December 24 and 27, compared with the daily average of just 4,000, figures from the Department of Health showed.

England's Chief Medical Officer Professor Liam Donaldson said most callers sought advice on treating influenza and cold symptoms.

A statement from the Department of Health said the figures were still well within the average flu rate for this time of year.

A spokeswoman said: "The largest ever flu immunisation programme started this year at the end of October.

"Nine million doses were made available for vaccinations through the NHS, one million more than last year.

"The Chief Medical Officer, Professor Liam Donaldson, has asked doctors and nurses to ensure that all `at risk' patients are offered the vaccine.

"These include everyone aged over 75, people with chronic respiratory disease and other serious conditions and everyone living in long-stay residential accommodation.

"Although an increase in flu cases puts extra pressure on the system, the NHS anticipated this increase in demand and has planned accordingly.

"The NHS has been planning for this winter period and the extended millennium holiday for the past year and is better prepared this winter than ever before.