Photos of dirty trains in China have been widely shared on Chinese social media as smog continues to blanket the country.
The original images were taken by a photographer from The Economic Daily newspaper however the images prompted many people to post their photos of dust covered trains to Chinese social media.
The response has prompted officials to reply to the questions on how the trains managed to be covered in so much dust.
A photographer from The Economic Daily newspaper took the images while travelling from Shanghai to Beijing on Wednesday. The majority of this journey went through the current red smog alert zone.
China's high-speed trains travel at their highest speed at 300km an hour. The journey between the two cities takes around five hours on average.
The images prompted people online to post their own images of filthy trains travelling through northern China.
Midwest IT Guy, Midwest, about 3 hours ago
Surely there is a more efficient way to clean a train other than a rag on a stick? Maybe some kind of 'Spray Only" car wash like tunnel built over the tracks?
PerAxel, Goochland, United States, about 3 hours ago
These jobs give people an income. They do work and they then get paid. Automation replaces them.
P6059, Falmouth, United Kingdom, about 5 hours ago
You should see the buses in Cornwall, GB. ****buckets all of them!! Trains are no better either.
phlpa81, Cherry Hill, United States, about 6 hours ago
I wonder how often they need to replace the air filtration system.
GTUSA, THE OC, United States, about 5 hours ago
s.gee, staff, United Kingdom, about 8 hours ago
Trains I've seen today in UK are much dirtier than the one in the photos...
ottokatz, meriden, about 6 hours ago
But this Chinese train is after one run. How often do the UK trains get washed?