National Rail said disruption is expected until at least 6pm.
Routes affected are those travelling bween Stoke-on-Trent and Macclesfield and Crewe, including Avanti West Coast services.
“The emergency services are dealing with an incident between Stoke-on-Trent and Macclesfield / Crewe,” a statement read. “To allow them to safely access the railway and carry out their work, all lines running between these stations are currently closed.
“This means that trains may be cancelled in full, delayed, revised or diverted.”