Train services on Wellington's Johnsonville Line have been suspended following an incident that left people injured.

A Metlink alert said services on the line were suspended "until further notice due to a major operational incident".

"We are working on sourcing buses at this stage. Updates to follow," the alert said.

Fire and Emergency New Zealand confirmed it was attending an incident involving a train. Three fire appliances are at the scene.

People had been removed from the train, a spokesperson said. No one needed to be extricated.