One person was killed and over 25 others were injured in an explosion in Assam's Dibrugarh district Sunday evening, police said.Dibrugarh Superintendent of Police Rana Bhuyan said the explosion took place at Rajgarh area. "There was an explosion but we are yet to ascertain its exact cause," he said adding that all the injured were rushed to the hospital.The Assam government had already ordered a probe into the incident and Chief Minister Tarun Gogoi had already asked the state Parliamentary Secretary (Home) Atuwa Munda to rush to the area."Police are yet to ascertain about the cause but the locals have claimed it to be a blast," Munda said.Prime Minister Narendra Modi and Home Minister Rajnath Singh are expected to visit the state Nov 29-30 to take part in the All India Directors-General of Police conference, which will be held in Assam's main city of Guwahati.