The forensic report obtained by the National Investigation Agency states that a substance called arsenic sulphide was used in the bomb found on the railway track at Ghorasan in Bihar. A chemical that is used in firecrackers was found in the pressure cooker bomb that was planted on the track.
The bomb was planted on the track on October 1 last year. However, villagers found it and after reporting the same to the police the bomb was defused. In February it was the Bihar police which first brought to light an Inter-Services Intelligence hand in the incident.
Three persons were arrested by the Bihar police and during their questioning, it was revealed that they had planted the bomb at the behest of an ISI operative in Nepal.
Shamshul Hoda, the ISI operative arrested by the Nepal police confessed to his role in the Ghorasan incident. He, however, ruled out playing any role in the Kanpur and Kuneru train accidents in which nearly 200 people had died.