She went missing after the blast at the Ariana Grande show.
ScotRail Cutting Sunday Timetables
ScotRail bosses are reducing the number of trains that will run on Sundays because of a shortage of available drivers.
The train operator is to publish a new reduced timetable for Sundays which will come into force from this weekend.
Phil Verster, managing director of the ScotRail Alliance, insisted the decision to scale back services had not been taken lightly.
But with the operator currently relying on drivers volunteering to work Sunday shifts, he said they had to "be able to give our customers certainty about which services will be running and which ones won't''.
While services on Sunday are partly dependent on drivers volunteering to work, the number who are prepared to do so is said to have declined steeply in recent days as a result of ongoing pay negotiations.
ScotRail has offered drivers a 2.5% pay rise, together with a one-off bonus of £500 for ensuring Sunday services are covered.
The offer, which is said to amount to a 3.7% wage rise for 2015/16, has yet to be accepted.
The rail operator also plans to recruit up to 100 new train drivers in a bid to ensure that Sunday services in the future are not dependent on staff volunteering to work.
Mr Verster said: "We have inherited a business that runs a seven-day railway with a system of staff rostering that covers only six days.
"Our customers want the same level of service right throughout the week, so we have to make changes and improve our railway.
"We cannot expect our train drivers to volunteer for so many Sundays when our rosters should reflect a modern, seven-day railway for Scotland.
"We have made an offer to our train drivers that would see them get more pay, have less weekend working and have a better work/life balance.
"Our further commitment to employ up to 100 new train drivers will make our Sunday services robust.
"I sincerely hope we can reach an agreement with our train drivers and our unions on this proposal.
"A 3.7% total pay offer is substantial and our commitment to make Sundays a part of the working week modernises our railway and is a significant work-life balance benefit for our train drivers.
"We do not want to reduce the number of services on a Sunday or any other day. It is not a decision that we take lightly, but we must be able to give our customers certainty about which services will be running and which ones won't.
"We really want to get the situation resolved and we remain open to discussing our proposals and options with our unions.''
ScotRail has set up a dedicated webpage at www.scotrail.co.uk/sundays where details of the temporary Sunday timetables will be available from tomorrow.
Family members say Laura Macintyre and Eilidh MacLeod haven't been heard from since the explosion.
The families of two girls from the Western Isles missing after attending the concert in Manchester targeted in a terror attack have issued appeals on social media.
Crews were called to the former Royal Victoria Hospital site this afternoon.
Most Viewed Pictures On Heart
Recently Played Tracks
To listen live, choose your preferred station:
Now playing: The best feel good music
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.
Find out more about some of the companies advertising on Heart Scotland- East.