Switzerland's main north-south rail link will stay closed for days after a landslide on Wednesday near the site of a similar incident in June, national train operator SBB said.

"Train services have been halted since around 4.30 pm on the St Gotthard line after a landslide" near central Switzerland's Gurtnellen, SBB said in a statement.

"The interruption will last several days," it said, adding that the incident occurred "near where another landslide happened in June".

Unlike that previous incident, in which a rail worker was killed, no one was hurt in the latest landslide in which 150 cubic metres (almost 5,300 cubic feet) of rocks fall onto the tracks, SBB said.

No trains were passing at the time of the landslide and early warning systems had functioned properly to halt all services in time, the rail operator said.

While the line stays closed, passenger and freight trains are to travel via the Simplon tunnel -- another major axis.

On average, 120 freight trains use the line every day.