After being tipped off by a telephone call, the Bomb Squad of Kerala police rushed to spot and took away the object from the northern end of the bridge and found that it contained some powdered chemical, two PVC pipe pieces, two batteries, a detonator and a plastic timer that looked like a small clock.
Police said the chemical appeared to be ammonium nitrate. It had been sent to the Government Forensic Laboratory in Thiruvananthapuram for detailed analysis.
The bridge spans the Muvvattupuzha river near a major plant of the central public sector Hindustan Newsprint Limited, Velloor. It is located in a busy rail route between Kochi and the state capital.
Train traffic between Kottayam and Ernakulam was disrupted for over an hour in the forenoon after the object was spotted.
Security had been stepped up in all trains passing through the state's railway stations in the wake of the incident.
A case had been registered and an investigation is on by police headed by a Deputy Superintendent of Police.
Train services were resumed after police took away the object for examination and the track was found safe after a thorough search, police sources said.
