Charred remains of a Hyderabad-bound private bus that caught fire after a collision with a two-wheeler, near Chinnatekur in Kurnool district, Andhra Pradesh. NEW DELHI: The blaze that engulfed a passenger bus in Andhra Pradesh in the wee hours of Friday was sparked when a motorcycle came under the vehicle and was dragged along, leading to the fire, according to police.The fire claimed 20 lives — 19 passengers on the bus and the motorcyclist.“Based on forensic analysis, post-mortem reports, scene reconstruction and witness statements, the sequence of events leading to the bus fire has been established,” the Office of the Superintendent of Police, Kurnool district — where the mishap occurred — said in a press release. Investigators found that the bus driver, Miryala Lakshmaiah, had collided with a motorcycle travelling in the same direction. The motorcyclist, Bucchalu Shiva Shankar, died on the spot.“The bike was dragged under the bus and the sparks from this resulted in the fire. The bus batteries, presence of flammable furnishings in the bus and the cargo consisting of cell phone aggravated the fire leading to the tragic event,” the release stated.It added that families of 18 of the deceased have been contacted, and the process of DNA matching and handing over the bodies is currently underway. The bus, carrying 43 people, was travelling from Hyderabad to Bengaluru when the accident occurred.A case has been registered against both drivers of the bus for alleged negligent and over-speed driving, based on a complaint by one of the survivors, N Ramesh.