(CNN) -- Police rescued seven people from the wreckage of a bus that hit a culvert and burst into flames in southern India on Wednesday, authorities said.
The overcrowded bus with 49 people aboard was traveling from Hyderabad to Bangalore city when the accident happened, said police superintendent Nagendra Kumar.
While speeding and trying to overtake another car, it hit a culvert and its diesel tank burst into flames, Kumar said.
Of those rescued, five are undergoing treatment at a local hospital.
The private bus has 29 seats, but a passenger list of 33 people, according to Kumar. The number of fatalities was not immediately available. Extra passengers may have boarded along the way, bypassing the number on the list.
The accident occurred in Mahbubnagar district.
"This is the first time an instance of this magnitude has occurred in Mahbubnagar -- we have never seen anything like this before," Kumar said.
India has an appalling record when it comes to road traffic deaths. In 2011, more than 142,000 people were killed in about 490,000 road crashes, according to the country's transport and highways ministry.
This equates to almost one accident per minute and one death every four minutes on India roads -- making it a bigger killer than HIV/AIDS and other diseases, according to the World Health Organization.