The mystery fever that has gripped children in Bihar's Muzzafarpur district has been diagnosed as encephalitis even as the virus claimed three more lives, taking the toll to 36.

Two children died at Kejriwal Hospital, while another died at Srikrishna Medical College Hospital (SKMCH) here, official sources said.

Thirty-three children had died due to the fever in Muzaffarpur district , the sources said. A Central team, which had collected blood samples of the patients to ascertain the cause of the deaths, said that it was clinically diagnosed that the children were suffering from encephalitis.

"We can say the reason of the death of children is encephalitis but at this stage it is difficult to say what sort of encephalitis it is, whether it is viral one or Japanese", Dr I P Choudhary, member of the Central team, told reporters.

Another member Dr B P Tambley of ICMI New Delhi also subscribed to Dr Choudhary's view and said it has been clinically established as cases of encephalitis caused by Culex mosquito which was found in the surroundings.

Eighteen children were still undergoing treatment at the two hospitals, they said.

A seven-member Central team from National Institute of Virology, Pune and ICMI, New Delhi, comprising experts including Union Health Ministry Joint Director S K Jain, B R Thappa and I P Choudhary visited the SKMCH and took the blood samples of children affected by the disease.

Jain said the blood samples would be sent to specialised virology labs in Pune and New Delhi and the examination report would be made available within a fortnight.

Authorities have been advised by the Central team to shift the children afflicted with the disease to the air-conditioned ward of the hospital.

The Central team also visited the affected villages and enquired about the food habits of the affected children from their guardians besides inspecting the surroundings.

Union Health Minister Ghulam Nabi Azad sent the Central team of medical experts from Pune and New Delhi to Muzaffarpur following request from Chief Minister Nitish Kumar to examine the patients and work out ways to prevent the spread of unknown fever.