Rail passengers "deserve better" after recent disruptions to services, the transport minister has said.

Humza Yousaf made the comments during a visit to Edinburgh Waverley station to view work on upgrading services between Edinburgh, Helensburgh and Milngavie.

The minister has come under attack from opposition parties over the reliability of ScotRail trains in recent weeks, with Yousaf apologising to passengers in the Scottish Parliament and demanding Dutch operator Abellio improve its record on service disruption.

Visiting the £19m Waverley project on Tuesday, Yousaf reiterated his "250-point plan" would be published shortly and ScotRail would be expected to act upon it.

He said: "Passengers expect better and we're investing in train technology, track operations and hopefully they will see that improvement.

"I understand passenger frustration. The standards that they expect are not being met and the standards that I expect ScotRail to meet are not being met either.

"So, I understand their frustration but improvements are being made here and now.

"If you take the last eight-week period there has been an improvement from 89.5% to 89.9% of that [performance and punctuality measure] figure, but I want to see more improvements and I want to see passengers have a better experience right here right now."

Yousaf added: "Passengers and commuters in Scotland certainly deserve better but let's put that into some context.

"Trains in Scotland are running better than across the rest of the United Kingdom. Also, our satisfaction is better, too.

"Things are not as good as they should be and standards are not as good as I would expect, but there's an improving picture and I want to see it continue improving."

The latest upgrade of the fleet of c334 trains will increase the number of six-car trains able to run on the network and improve reliability, Transport Scotland said.

Phil Verster, ScotRail alliance managing director, said: "It is another milestone achievement in our overall train improvement programme, which sees £475m spent on refurbishments and new trains for Scotland's railway.

"We are going through the biggest improvement in our railway since the Victorian era and this investment in our rolling stock is another significant signal of our determination to deliver a railway of which Scotland can be proud."

The opposition has been approached for comment.