Around 22 firefighters have spent the past few hours tackling a blaze at a building just off Gorseinon Road.
The alarm was raised at just after 5.27am this morning.
Motorists were advised earlier to avoid the area.
Fire crews are currently dealing with an incident on Gorseinon Road, Penllergaer. Avoid the area due to a number of appliance in attendance. #JFControl— Tân CGC / MAWWFRS (@mawwfire) June 11, 2019
Five appliances are at the scene.
Three main jets, two BAs, one hose jet and one aerial appliance.
Gorseinon Tyre and Service Centre has notified customers that it is shut due to an incident at a neighbouring building. It posted this message on Facebook.