Abdullahi Mustapha Berende, presented as a leader of the Shiite sect in the central city of Ilorin, was arrested last December "for his active involvement in espionage and terrorist activities," state security service spokeswoman Marilyn Ogar said.
Investigations revealed that Berende, accused of establishing a "terrorist cell" in Nigeria's southwest, with a particular emphasis on Lagos, recruited the two other suspects for the task, Ogar said.
Berende underwent his training in Iran and his Iranian sponsors requested him "to identify and gather intelligence on public places and prominent hotels frequented by Americans and Israelis to facilitate attacks," she said.
He allegedly gave to his Iranian handlers the names of former dictator Ibrahim Babangida, and ex-supreme leader of Muslims in Nigeria, Ibrahim Dasuki, as targets for attacks that could "unsettle the West," she added.
His accomplices conducted surveillance and gathered data on the targets, ahead of the attacks, she alleged.
Berende denied involvement in espionage or terror-related activities but admitted seeking information about some individuals and institutions.
The institutions included USAID and the Jewish Cultural Centre (Chabad) in Lagos, Ogar said.
The suspects will soon be charged in court, she stated.