The victim was doused in kerosene by the Class 4 student and set afire in the hostel of G.A.V. School in Muzaffarpur, about 70 km from here.
"Angry over some dispute, a Class 4 student poured kerosene on the Class 3 student when he was sleeping and set him afire. The victim sustained 75 percent burns and his condition is critical," said a police official.
According to police, the incident took place a day after a heated exchange of words between the two, followed by a fight, Friday.
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