UPDATE: All issues have been resolved, Transpennine Express said in an update at 5.45pm.
There are problems on the trains through Manchester city centre this afternoon. An 'operational incident' is causing disruption between Piccadilly and Oxford Road.
All lines between the two station are affected, Transpennine Express said. Delays are expected to last until 6.30pm. Several services are showing delays of around two hours on the Transpennine Express website.
Transpennine Express tweeted: "Due to an operational incident between #ManchesterOxfordRoad and #ManchesterPiccadilly all lines are disrupted. Train services running to and from these stations may be delayed. Disruption is expected until 18:30."
A statement on the Transpennine Express website added: "We are sorry for any inconvenience this may have caused to your journey today."