Accident and Emergency (A&E) waiting times are their worst level for more than two years, official statistics show.

The latest figures from the country's hospitals show only 86.9% of patients were admitted, discharged or transferred within four hours during the week beginning December 10.

It is NHS Scotland's worst performing week in A&E waiting times since week beginning March 1, 2015, and well below the Scottish Government's target of ensuring 95% of patients are seen within four hours.

The health secretary, Shona Robison, has blamed black ice for the growing queues in A&E waiting rooms.

"Cold weather and particularly black ice is affecting the performance of our A&E departments and, while we expect waiting times to fluctuate from week to week in winter, there is no doubt that slips and trips and flu-like illnesses have significantly increased the pressures on our hospitals recently," she said.

Despite the minister citing increased pressures, official figures show no substantial rise in the number of people going to A&E departments.

During the week in question 25,840 patients attended the departments, a fall of five from the previous week.

On the same week in December last year, 25,338 patients were recorded as coming through A&E departments.

Scottish Conservative shadow health secretary Miles Briggs said: "The systematic failure of the Scottish Government to invest or support primary care has led to a predictable displacement of patient activity, driving up waiting times in emergency departments.

"The sad reality is that emergency departments cannot cope with this increase in patients, as well as seasonal pressures, so patients are waiting longer, many of whom are in serious discomfort."

Edinburgh Royal Infirmary was the worst performing hospital in the country for the second consecutive week, with just 64.1% of patients treated within the targeted time.

More than 120 patients had to wait double the expected time at the hospital while 48 patients at had to wait for over 12 hours to be seen.

Robison said: "We are specifically working with NHS Lothian to help identify and provide solutions to improve flow through the hospital, which in turn will boost its performance and improve waiting times for patients.

"Whilst we are in no way complacent, it is important to note the efforts of our hard working NHS staff.

"Scotland's yearly A&E performance is currently sitting at 92.9% and our core A&Es have outperformed those in the rest of the UK for more than two and a half years."