One person suspected to be involved in the Patna serial blasts was today arrested from Doranda locality in Ranchi by sleuths of National Investigation Agency (NIA), taking the total number of arrests to four in the Sunday blasts.

Assisted by Ranchi police, the NIA arrested one Ujjair Ahmad this afternoon, police sources said.

Three other suspects, identified as Tehsim, Imtiaz Ansari and Tabish, were arrested soon after the bomb blasts in the Bihar capital.

Director General of Police Rajeev Kumar yesterday said in Hazaribagh that six persons were detained for interrogation in connection with the serial blasts set off at and near the Gandhi Maidan ahead of the rally addressed later by BJP's prime ministerial candidate Narendra Modi.