"The bus was travelling from Nagpur to Pune when at around 1:35 am it met with an accident on Samruddhi Mahamarg expressway, after which the diesel tank of the bus caught fire," local police told Reuters TV partner ANI.
"The majority of deaths were caused due to burning."
Twenty-five people were killed and eight were injured, Maharashtra's deputy chief minister Devendra Fadnavis said in a post on Twitter.
The state's Chief Minister Eknath Shinde and Prime Minister Narendra Modi posted separate tweets expressing sorrow, and said they would pay support to each victim's family, amounting to 700,000 Indian rupees ($8,500).