ScotRail's service punctuality has improved but the train operator's performance is still falling short of a key target, new figures reveal.

More than nine out of 10 trains arrived at stations within five minutes of their scheduled time in the four weeks to February 4 - a 91.6% performance.

The rating is a 1.9% increase on the previous four weeks, a 2.3% rise on the same period last year and is the fourth consecutive period of improvement.

The figures also show the train operator's yearly punctuality target for the past 12 months is now 90.1% - short of the 91.3% required in its franchise contract with the Scottish Government.

ScotRail's yearly punctuality outperforms England and Wales, which stands at 87.4%.

Former ScotRail Alliance managing director Phil Verster, who quit his post last month after less than two years in charge, told MSPs days before he stood down that he expected the yearly target to be hit by March.

Transport Minister Humza Yousaf said the new figures are "encouraging" but that the yearly target is "not quite where we would want it to be yet".

He added: "It is, however, encouraging to see four continued periods of improvement, especially during the winter period.

"Working with the industry, we remain focused on ensuring the performance improvement plan is implemented effectively and real improvements continue to be seen over the next few months."

Perry Ramsey, ScotRail Alliance operations director, said: "Right now, across Scotland, we are working round the clock to deliver improvements that will transform our railway. This is one of the biggest, most ambitious upgrades of the network since it was built in Victorian times.

"Today's figures show that, despite the huge challenge of this work, we are continually improving the service we deliver to our customers, every single day. This is demonstrated by the fact performance is up, not just on a month-to-month basis, but on the same period last year.

"It is now clear that the Performance Improvement Plan, introduced late last year, is working and we will continue to keep customers at the heart of everything as we seek to consistently improve our performance."