The Uttar Pradesh Anti-Terror Squad on Wednesday detained three people in connection with Tuesday's blast in Varanasi which killed a one-year-old child and injured at least 20 people, a media report said.
According to CNN-IBN, the ATS has identified Mohammad Shahnawaz, (27), a doctor and Asadullah Akhtar alias Asadullah Khan, (25), a pharmacist, as key suspects behind the blast.
Both are allegedly linked to the 2008 Delhi blasts and the Batla House encounter in Delhi.
Indian Mujahideen (IM) claimed responsibility for the blast in an e-mail traced to Malad in Mumbai.
Earlier a father-son duo were picked up for questioning in Mumbai in connection with the e-mail sent by IM.