The bus driver was among the persons killed in the accident.
At least 10 people died and several were injured when the bus in which they were travelling collided head on with a book-laden truck in Nalgonda district of Telangana late on Wednesday afternoon.
The bus driver was among those killed. Locals said overspeeding by the lorry driver had caused the accident.
The accident took place near Indirapalanagar, around 100 km from state capital Hyderabad, officials said.
The bus belonged to the state-owned Telangana Road Transport Corporation and was on its way to Nalgonda.
Eye-witnesses said many of the injured were in a critical condition.
State Home Minister N Narasimha Reddy and Transport Minister Mahender Reddy have left for the accident site.