Arriva Trains has confirmed that its Cambrian line will be replaced by a bus service all week and into the weekend.
The company said that Network Rail started track and signalling improvement work between Shrewsbury and Pwllheli on Saturday and will continue until Sunday, March 27.
Its spokesperson said: “No Arriva Trains Wales services will operate and a replacement bus service will be in operation at this time for Welshpool and Newtown passengers.
“We advise passengers intending to travel to enquire before starting their journey for full details of altered trains, onward connections and additional road transport.”