A remote device was used to carry out the bomb blast in Allahabad that killed one man and severely injured five, including Uttar Pradesh Institutional Finance (Stamps and Registration) minister, Mr Nand Gopal Gupta, alias Nandi, police said here on Tuesday.
"Anti-Terrorist Squad (ATS) sleuths have gathered enough evidence indicating use of a remote device to detonate the bomb," a top police officer said.
"The fact that the bomb exploded just when the minister was walking past that spot clearly shows that someone was keeping an eye to trigger a remote device," he said.
Investigating agencies comprising the ATS and the Special Task Force (STF) were stated to be working on the theory of a deep-rooted conspiracy behind the blast that was meant to target the minister.
Mr Nandi, 36, is the youngest member of the Mayawati cabinet. Despite being a first-time MLA, he was rewarded with a ministerial berth, essentially because of the devastating defeat of two powerful rivals in the 2007 assembly elections.
Both Congress state president, Ms Rita Bahuguna Joshi, as well as former BJP state chief and party veteran, Mr Keshari Nath Tripathi, were humbled by Mr Nandi at the polls.
It was a rags-to-riches story for Nandi, who began his career as a pavement seller to rise to chairman of multi-crore rupee Nandi group of industries.
He was also stated to be involved in real-estate and money-lending, that was believed to be somewhere deep behind the murder attempt.