Four people, including three alleged Maoists, were detained in Bihar for suspicious activities ahead of Prime Minister Narendra Modi's day-long visit on Saturday, police said.
The intelligence agencies have warned of a possible "human bomb attack" on Modi on the lines of former prime minister Rajiv Gandhi's assassination, a top police officer said.
"One of the suspects is from Jammu and Kashmir. He was detained in Patna's S.K. Puri area on Saturday morning," an officer said.
The alleged Maoists were detained in Muzaffarpur where Modi will address a public meeting. Tight security arrangements have been made and the area has been turned into a fortress, police said.
Bihar Chief Minister Nitish Kumar will welcome Modi at the Patna airport.
Modi will launch five projects, including Pandit Deen Dayal Upadhayay Rashtriya Gramin Joyti Yojna and inaugurate the new campus of IIT-Patna.
He would also attend two other functions in Patna before leaving for Muzaffarpur, around 70 km from Patna.
Modi's rally at Gandhi Maidan here was rocked by serial bomb blasts on October 27, 2013, leaving five people dead and nearly 100 injured.
