Arriva Trains Wales have confirmed rail services between Swansea and Llanelli have been suspended, because of a large fire near the train line.
It's thought to have started just before 6am this morning at the Fforestfach Industrial Estate in the city.
Police are urging people to avoid the area.
Firefighters have extinguished the blaze at a scrapyard at Fforestfach Industrial Estate. The fire involved over 4,000 tyres.
Over 70 firefighters are currently tackling the fire, which is now confirmed to be at a scrap yard.