"Prima facie it does not appear to be the handiwork of Maoists in the Rajdhani derailment at Chapra," Manjhi told reporters. (JPN/Agencies)
"No trace of blast on the track or any other evidence suggesting sabotage has been found so far," he added.
Manjhi said that he spoke to Railway Minister Sadananda Gowda about the incident.
He questioned why a pilot engine was not run ahead of Rajdhani Express as per standard practise in the Maoist-hit region.
"The incident appears to be a result of error on the part of Railways," he said.
Expressing grief over the loss of lives, Manjhi announced a compensation of Rs 50,000 to the next of kin of the dead.
He also announced free medical treatment for the injured taken to the Patna Medical College and Hospital (PMCH) from Chapra.
Meanwhile, Director General of Police (DGP) P K Thakur also ruled out involvement of Maoist behind the mishap.
"No indication of blast or live bombs have been found from tracks from near the incident site so far," said Thakur, who assumed duty as DGP on Tuesday.
He said Additional Director General of Police, Rail, K S Dwivedi has been sent to the spot in Chapra for investigation.
Dwivedi, who was on his way to Chapra, said that he has already dispatched a forensic and bomb disposal team.
At least four passengers were killed and eight injured when the New Delhi-Dibrugarh Rajdhani Express derailed at Golden Ganj station near Chapra early on Wednesday.
"Prima facie it does not appear to be the handiwork of Maoists in the Rajdhani derailment at Chapra," Manjhi told reporters.