Image copyright SNS/PA Image caption ScotRail says the delayed arrival of new electric trains has put pressure on staffing

Nicola Sturgeon has branded the number of cancellations and delays to ScotRail services in recent weeks as "unacceptable".

The first minister said the public was owed an apology for a series of problems on Scotland's rail network.

Hundreds of services have been cancelled or had fewer coaches, leading to overcrowding, since the introduction of a new timetable.

Ms Sturgeon said travellers deserved better.

Speaking at First Minister Questions, she said: "We've seen a significant and unacceptable number of delays that are clearly the responsibility of ScotRail.

"I can report to parliament that cancellations of this type have fallen as the week has progressed from around 144 on Monday to an estimated 40 today.

"Progress is being made but it is not good enough - we expect, indeed we demand, better from the rail operator and the transport secretary continues to work closely with them to ensure that we continue to see improvements in the days to come."

"The level of cancellations, this week in particular, has been unacceptable and I absolutely recognise the frustration of the travelling public."

Image copyright Scottish Parliament Image caption Nicola Sturgeon said ScotRail had to make improvements

The new timetable, introduced on 9 December, promised the "best railway Scotland has ever had" with 100 new services and faster trains.

Refurbished Intercity 125s are coming into service, along with brand new Hitachi class 385 electric trains.

But the network has been besieged by problems since and ScotRail has apologised and promised service improvements.

'Worst point for 12 years'

Scottish Conservative deputy leader Jackson Carlaw said: "We've got new official figures that show that since 2011 there have in fact been more than 35,000 cancellations or part cancellations caused entirely by ScotRail, that amounts to some 5,000 a year.

"Punctuality on our train service reaching its worst point for 12 years, hundreds of trains cancelled and shortages of staff because people are being trained to use the new class of trains which are also delayed, causing another 100 services to be cut last month.

ScotRail Alliance managing director Alex Hynes previously said that problems in training staff to operate new trains were the main reason for recent delays.

He added: "We're sorry to customers for the disruption to services in recent weeks. We know the impact this has on your day, and are working flat out to get things back to normal.

"Training is ongoing so that we can get services back to normal and we can expect an improvement in the coming weeks. But while we continue to train our conductors and drivers some disruption will remain.

"We know this isn't acceptable, and are sorry to customers about this. Every single person at the ScotRail Alliance is working hard to improve things for our customers as soon as possible."