Flu cases in Scotland this winter have more than doubled compared to the same period last year, putting pressure on NHS services around the country.

New statistics published by Health Protection Scotland (HPS) show around 46 Scots in every 100,000 were suffering from the virus during the last week in December 2017.

This compares to 22 in every 100,000 for the same week in 2016.

The report also found that around half of NHS Boards are reporting significant pressures as a result of the virus.

At the Queen Elizabeth University Hospital in Glasgow, 15 operations had to be cancelled on Thursday due to the additional strain on services.

Jane Grant, chief executive of NHS Greater Glasgow and Clyde, apologised to affected patients.

She said: "We planned for these winter pressures by creating extra capacity - such as extra inpatient beds at Gartnavel Hospital and restricting staff holidays. Our winter plan is designed to create extra resilience and enable us to respond to these additional pressures and open additional in-patient beds where appropriate.

"These winter beds are currently being used as part of our response to the winter pressures we are experiencing.

"We accept that a number of our patients have waited longer than we would have liked. However, this is due to the high level of demand and we apologise to those patients who experienced lengthy waits. When our patients are kept waiting for admission to hospital they are still receiving care from our doctors and nurses."

Earlier this week, figures revealed A&E attendances at Scottish hospitals were up by a fifth on last year.

The Scottish Ambulance Service and NHS 24 also reported spikes in call volume over the festive period.

Health secretary Shona Robison praised NHS staff for their hard work over what she called "an exceptionally busy winter period".

She said: "Health staff across Scotland are dedicated to helping patients and are doing a fantastic job in difficult circumstances. These figures show once again the challenges they are tackling.

"So far the vaccine is proving to be effective against the most commonly encountered flu strains this season although it is still too early to have a complete picture -but there's no doubt that the increase in cases, particularly affecting people with complex and multiple conditions, is putting increased pressure on our systems."

Ms Robison went on: "It is important for patients to be aware that while health boards continue to take all appropriate steps to respond to increased demand in line with their winter plans - which may include some deferral of non-urgent elective surgery - there is no blanket cancellation of non-urgent elective procedures for the month of January as is the case in England.

"The public can also support our NHS staff by following the sensible health advice that is available through NHS Inform."