There are currently delays on the trains due to a fallen tree blocking the railway line near Dronfield.
It is disrupting trains on the Sheffield/London and Liverpool/Nottingham/Norwich routes.
A specialist team are on site and making arrangements to remove it, East Midlands Trains said.
A spokesperson for East Midlands Trains said: "Whilst the team remove the tree from the railway line near Dronfield some of our trains will be diverted with extended journey times of up to 20 minutes. The line is expected to be reopened by 12.15pm."