The Bangkok Metropolitan Administration (BMA) and the State Railway of Thailand (SRT) have sent a 30-strong team to clear rubbish along rail tracks near Phaya Thai after a Japanese netizen posted pictures of a Kiha-183 train, donated by Japan to serve tourists, passing through an apparent dump site in the area.
Twitter user @tabinezumiworld posted the picture on Sunday with a message saying it showed the gap between rich and poor in Bangkok.
The area is to be used for building a new elevated train line.
In a subsequent comment, he also posted a message in both Japanese and Thai that he knew that homes had recently been demolished for the new project.
He also noted that "There was broken glass, pieces of concrete and leftover food," and he wondered when all this rubbish would be collected.
"It is unsanitary and has a bad odour. I hope for a speedy resolution. I urge the Thai government, City Hall and SRT to take action," he tweeted.
The post was picked up by ThailandFootpath Facebook, which has more than 300,000 followers and also later carried by mass media.
Bangkok governor Chadchart Sittipunt on Tuesday responded to the outcry by inspecting the area himself.
He said the piles of garbage along the railway are a result of the demolition of about 100 homes of local communities living illegally along a 1.2km stretch of track.
Mr Chadchart said the demolition took place last month to pave the way for the construction of the Don Mueang-Suvarnabhumi-U-Tapao high-speed rail route, but after the demolition, the rubbish had just been left there.
Ekkarat Sriarayanpong, head of the SRT governor's office, said that the SRT and BMA had sent a 30-strong team to clean up the area, and a backhoe tractor and trucks were used to remove and transport the waste from the area.
He said that SRT will set up a fence and will also put up "no trespassing" signs to stop any intruders and those who may throw away their own rubbish in the area.
A Kiha-183 train donated by Japan runs along tracks in Phaya Thai district, which are strewn with rubbish left behind from the demolition of illegal houses located on both sides of the tracks. The rubbish has since been removed. photos by State Railway of Thailand