No casualty was reported in the blast that took place late last night, said Deputy Inspector General of Police, Magadh range, P K Shrivastava.
In Patna, Chief Public Relations Officer, East Central Railway, Arvind Kumar Rajak said the advance pilot engine running ahead of Bhubaneshwar-New Delhi Rajdhani Express jumped off the track due to the incident.
Nearly one dozen mail and Express trains including three Rajdhani Express trains have been stranded at various places between Gaya and Mughalsarai due to the incident, Rajak said.
The blast was trigerred during a one-day bandh call called by the Maoists against police firing in Aurangabad and Rohtas districts.
The CPRO said that nearly three metre of the track has been damaged in the blast. Electric wire overhead has also been damaged, he said.
The DIG said that the blast appears to be a powerful one creating a four-feet deep crater.
Howrah-New Delhi Rajdhani Express, Bhubaneshwar-New Delhi Rajdhani Express, Sealdah-New Delhi Rajdhani Express, Jodhpur-Howrah Express and Doon Express were among the major trains stranded at various places.
The blast took place at Lahat village under Rafiganj police station of Aurangabad district at around 11:30 PM last night.
Gaya Additional Superintendent of Police Ashok Kumar Singh, who rushed to the spot after the incident, said the explosion took place during the one-day bandh call given by the Naxals against police firing in Aurangabad and Rohtas districts recently.
The bandh was called from midnight last night till midnight tonight.
The ECR CPRO said that DN line has been restored in the early hours today and work was on to make the UP line, which bore the brunt of the explosion, functional during the day today.
The Magadh range DIG said that security has been tightened through deployment of additional forces to prevent untoward incidents during the bandh.
Two persons each were killed in police firing on a mob in Rohtas as well in Madanpur area of Aurangabad within a fortnight.
The Aurangabad firing was triggered during an anti-Naxal operation by CRPF.Those killed included a woman and a minor boy in Aurangabad last week.
The Rohtas firing was triggered when a mob protested against alleged one-sided action after an exchange of "objectionable" MMS between two friends belonging to different communities.
Opposition BJP has made a hue and cry over both the firing incidents in the bicameral Bihar Legislature demanding judicial inquiry in the incidents.
The state government defended the firing as part of self-defence by security forces who were targeted by a mob.