Student groups have attacked several high schools and junior colleges mostly in the capital, Katmandu, this month. They accuse managers of charging high fees, running misleading advertisements and giving the institutions foreign names such as "Liverpool," "Cambridge" and "Florida" to lure students.
Attackers damaged property and set school buses on fire on two occasions.
The U.N. statement says the most recent attacks on school buses could have had disastrous consequences as some children were inside.
It urges authorities to investigate the attacks and identify those responsible. Attacks by student groups are rarely investigated by Nepalese authorities.