One-year-old Sapna Khatoon died Monday of suspected AES at the Sri Krishna Medical College and Hospital (SKMCH) in Muzaffarpur, about 70 km from here.
Sapna's father Mohammad Jalaluddin, a resident of Sirsia Kalyanpur village in East Champaran district, said she was admitted to the hospital after her condition deteriorated.
A district health official in Muzaffarpur said that 10 children with suspected AES were admitted to various hospitals in the district in the last two days.
While three children have been admitted to the Kejriwal Hospital, seven are undergoing treatment in SKMCH, the official said.
"Every year, encephalitis hits Muzaffarpur, Gaya and other neighbouring districts in May or June. But this year it seems to have hit a little early," a health department official here said.
Last year, the acute encephalitis syndrome (AES) killed nearly 240 children in Muzaffarpur and Gaya districts.
AES is a severe case of encephalitis characterised by inflammation of the brain.
Last week, the state government had launched a special vaccination drive to cover 1.8 million children against Japanese encephalitis.