An operation to tackle a major blaze at a recycling unit in Swansea has been scaled down, the fire service has said.
The fire at M & R Commercials in Felinfach Industrial Estate, Fforestfach, involving 4,000 tyres, cylinders, waste and scrap vehicles, started at about 06:00 BST on Monday.
Residents were told to keep doors and windows shut and to keep away from the immediate vicinity of the incident.
Trains between Swansea and Llanelli on the south Wales mainline are disrupted.
About 70 firefighters were tackling the blaze at its height, but the number of water pumps has now been reduced from 10 to three, Mid and West Wales Fire Service said.
The service established an incident command unit at the scene and a spokesman said all the special units remained there.
He said they had made “significant progress” in controlling the fire, but crews would remain on site for the rest of the day “dampening down and liaising with partners on returning the site to normal operation”.
An Unmanned Aerial Vehicle is being used to help them get closer to the fire so they can “turn it over” and reach “the deep seated areas” where the fire is still burning.
As they do this, MWWFS said, it may appear as though the fire is getting worse but it is just part of the dampening down procedure.
He said there was no current risk to local residents or commercial premises, and police were continuing to maintain cordons for the duration of the incident.
The main railway line has been reopened but passengers could face residual delays.
An Arriva Trains Wales spokesman said: “Trains are proceeding at caution, however, disruption may last some time with the knock on effect this has had on services.”
Natural Resources Wales will investigate the incident and advised M & R Commercials to “further reduce the impact of the fire”.
“Our operational team have installed booms to reduce the impact of contaminated water entering the Fforestfach Stream,” Jonathan Jones, NRW lead for the incident, said.
“Our air quality expert is working with Public Health Wales and the local authority to manage the risks to air quality.
“We are investigating and advising to protect the environment and the local community from pollution caused by the fire.”
Roads around the industrial estate are also closed and South Wales Police is advising people to avoid the area.