As soon as the bag was spotted near suburban Tambaram Sanatorium Railway station,government railway police personnel arrived on the scene with bomb disposal experts.
"The bag contained 350 lithium batteries. There was no explosive material. Forensic experts too examined the bag and ruled out explosive substances," Superintendent, Government Railway Police, P Vijayakumar told PTI.
The smoke may have been due to "overheated" batteries or other technicalities, police personnel who visited the spot said.
They said an inquiry was on to find out who abandoned the bag, though there was no explosive substances in it.
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