Accident and emergency (A&E) waiting times have risen amid a surge in demand over the festive period.

The latest figures for the week ending December 17 show 81.1% of patients were seen and either admitted, transferred or discharged within four hours, significantly short of the Scottish Government's 95% target.

It represents a drop from 86.9% the previous week and is down from 90.2% in the same week last year.

Attendances were up 12% on the previous week and 15% on the same week last year, with much of the increase attributed to weather-related slips and trips and seasonal illness.

The statistics show there were 29,054 attendances at emergency departments across Scotland during the week - the highest number since weekly reporting began in 2015.

Much of the rise in demand came towards the end of the week.

Raigmore Hospital in Inverness and Aberdeen Royal Infirmary had 48% and 42% increases respectively in attendances between Thursday, December 14, and Sunday, December 17, compared with the same few days in the previous week.

Meanwhile, Hairmyres Hospital in East Kilbride reported receiving one week's worth of ice-related trauma demand in one day.

The Scottish Ambulance Service also recorded a 40% increase in calls to deal with trauma injuries during the week ending December 17 and, and over the weekend of December 16 and 17, a 60% increase in calls related to falls.

On a visit to Ninewells A&E in Dundee, health secretary Robison said: "I'm here at Ninewells to say thank you to all NHS staff working this festive season who are giving patients the best possible care in the face of exceptional pressures.

"Despite record numbers of people attending Scotland's A&E departments - up 3200 or 12% in just one week - A&E performance fell by a few percentage points.

"We are not complacent and are doing everything possible to improve that.

"Our additional £22.4m to deal with pressures this year is being invested into additional clinical and non-clinical staff to create extra resilience and maintain weekend and festive period patient discharges, so that there is sufficient capacity across the system."

Earlier this month, Robison, blamed black ice for the growing queues in A&E waiting rooms.

David Chung, vice-president of Royal College of Emergency Medicine (RCEM) Scotland said: "We have seen exceptional numbers of patients in the week before Christmas, which will undoubtedly affect how we are able to work through the festive period as well.

"RCEM is proud of the way those working in our emergency departments, and our other colleagues in health and social care, in their commitment and dedication over this festive period."

Scottish Conservative health spokesman Miles Briggs said: "Once again we are seeing waiting time figures get worse and worse."

He said figures for NHS Lothian, where 68.7% of patients were seen within four hours, were "especially concerning".

"It further proves that the SNP have totally mismanaged our NHS, and the situation won't improve until they start to seriously invest in primary care," he added.