The Haryana Police on Thursday said the blast in a private bus in Haryana's Fatehabad district on Tuesday was an "accidental" one.Additional Director General of Police Muhammad Akil said the explosion in Bhuna had been successfully solved by the police.Two persons received minor burn injuries in the blast.Akil told the media here that one Mukesh Kumar, who has been arrested, had purchased sulphur and potash and kept their mixture in a plastic bottle."The material was meant to be used to scare birds and animals from the fields by way of blast. This practice is not only followed in Haryana, but also in other states. A hole was made in the plastic bottle by Mukesh so as to prevent accumulation of gas. "But after boarding the bus, Mukesh Kumar felt that the gas was emanating from the bottle. He opened it to examine it and again kept it under his seat. "There is a possibility that the hole of the plastic bottle might have got blocked accidently, resulting in accumulation of gas and the explosion occurred. "However, the exact cause of the blast is still being investigated," Akil said.But the blasts in Kurukshetra and Panipat were criminal offences, he said.