Bengaluru, Dec 18 : NIA has seized 7.5 kgs of sodium nitrate chemical -- used for making explosives -- in Bengaluru on Monday from the residence of a law college student in Byadarahalli in the outskirts of the city. Sources said that the chemical was found at the residence of Shamiulla, a law student. The NIA took him into custody and continued the search operation. They said that Shamiulla had taken the house on rent in Prakruthinagar locality along with four others. One among them is an engineering student from a reputed college in Bengaluru. The arrest has raised the suspicion that the accused was preparing to carry out an explosion in the IT city. The NIA also conducted simultaneous raids on seven houses in Bellary city in north Karnataka in connection with alleged terrorist activities by the members of the banned PFI organisation. In these raids the NIA have arrested Ezaj Ahmad, Suleiman, Tabrez, Nikhil a.k.a Sufiyan, Muzammil into custody in Bellary. The sources said that the NIA is suspecting that the accused are trained in Afghanistan to carry out terror activity in India. The raids were underway when this report was being filed. NIA is yet to make an official statement in this regard. /IANS