The train driver received an alarm about a fire just before 11 am.
It was sensors that alerted about a suspected fire in part of the engine, says SJ's acting press chief Peter Kraméus to TT.
We haven't noticed it or felt that it would be a fire, but safety always comes first and then we have to stop.
Over 260 passengers are now being evacuated and will board another train to Stockholm.
The train stop is expected to cause delays in traffic on the southern main line, but they are not expected to be extensive.
