A crane has started to move derailed freight wagons from the track near Ely in Cambridgeshire.
Services to Peterborough from Norwich, Cambridge and Bury St Edmunds have been suspended while recovery work is carried out.
Engineers need to replace a section of damaged track before the line can be reopened. They hope the work will be completed on Monday.
Each empty wagon weighs 11 tonnes, with the heaviest container including its contents weighing 106 tonnes and each one will be carefully lifted onto the undamaged track to be towed away.
Simon Ancona, Network Rail’s chief operating officer for Anglia, said: “We have an army of experts and specialist teams who are working day and night to remove the wagons as quickly as possible.
"Once they are out of the way we can replace the tracks, carry out the necessary repairs, reopen the line and get passengers on the move again. We expect to be able to reopen the line on Monday. I’d like to thank passengers for their continued patience.”
The incident affects CrossCountry, East Midlands Trains and Greater Anglia passengers.