Police said a mini truck carrying a marriage party coming from Kandukur hit the bus coming from the opposite direction.
Fifteen people have been killed in the mishap after the bus caught fire in the mishap, Inspector of Police (Kandukur) M Lakshman said.
The mini truck was carrying 40 passengers while there were no passengers on board the bus. Fire tenders were pressed into service to douse the flames.
Andhra Pradesh Transport minister Sidda Raghava Rao also reached the spot and is supervising the rescue operations.
District Collector Sujatha Sarma also visited the mishap site.
The deceased were identified as -- N Subhasini (31), P Prasad (30), R Subba Rao (50), E Chiranjeevi (45), S Chandu (10), S Adinarayana (10), Srilakha (8), M Padma (40), K Sushela (47), S Venkateswara Rao (40), S Rajamma (40), V Subbaiah (30), V Chinnaya, S Rajayya, and B Hazarataiah.