Charanjit Singh, a resident of Kapurthala district in Punjab, was apprehended from the second terminus in Chandigarh on Friday afternoon, Inspector General of Police Satish Chandra said.
During the search, police recovered a mobile phone and a bag containing two pipe bombs and half-a-kilograms of explosive material, Chandra said, adding preliminary interrogation revealed that he had been trained in Pakistan and had spent six years in a Jammu jail.
After his release two months ago, Charanjit again came into contact with terrorist masterminds based in the United States and other countries and was asked to carry out the explosion in Chandigarh with the sole motive of spreading panic.
Chandra said Charanjit revealed that he was associated with Sikh terrorists groups and gradually became attached to International Sikh Youth Federation.
The ISYF men motivated him to go to Pakistan for training in 1999. In Pakistan, he met other terrorist leaders including Wadhawa Singh of Babbar Khalsa and Paramjit Singh Panjwar of Khalistan Commando Force Panjwar.
The IGP ruled out Charanjit's association with dreaded militant Jagtar Singh Hawara, who is in jail.