The bus hit a tree and slid into a ditch after it overturned, eyewitnesses said.
The injured are receiving intensive medical treatment at Tanjungpura general hospital in Langkat district, North Sumatra.
The students were supposed to attend a prom on the Hairos beach in Deli Serdang district.
Agus, one of the students, said the bus was running at a high speed when a speeding car and motorcycle came from the opposite direction.
"The driver got nervous and turned the wheel sharply to the right so the bus overturned and slid into a ditch," he said.
No fatalities were reported in the accident.(*)
Editor: Heru Purwanto
Copyright © ANTARA 2012
