Rail union leaders and railway managers are to attempt to settle their differences today as the first of two 24-hour strikes continued to hit thousands of commuters.

Around 450 Network Rail signallers and signalling supervisors in Scotland walked out for 24 hours from noon yesterday and will strike again tomorrow from the same time if the dispute remains unresolved.

The RMT says the row is over a move to change rosters at short notice, contravening an existing agreement.

Network Rail said the action centred on the issue of whether safety assessments should be voluntary.

The Rail, Maritime and Transport union and Network Rail management will meet for more talks today in an attempt to resolve the dispute.

The discussions, facilitated by arbitration and conciliation service Acas, are expected to take place at Network Rail's offices in Glasgow at about 2pm, just after the first strike ends.

Last-ditch talks aimed at stopping the strike collapsed yesterday after no agreement could be reached on the dispute.

Scottish First Minister Alex Salmond last night said: "It must be a good sign that both sides are willing to resume talks and I welcome this development.

"It is deeply unfortunate that one remaining issue in the dispute has resulted in substantial inconvenience to the travelling public.

"Both the union and management must do their utmost to resolve their differences and avoid a repetition of the action."