Mathura, Oct 22 Railway Minister Mamata Banerjee has decided to direct a CBI inquiry into Mathura train accident mishap.

"Realising the gravity of the accident, I have decided that it is better to go for a CBI probe," Bannerjee said last night during a visit to the site.

"Many questions have cropped up. Somebody is saying that chain-pulling was the reason for the accident and others say there was a problem in the signal. It may be a case of criminal offence also. So, I have decided that we must hand over the case to CBI," she added.

Meanwhile, the Uttar Pradesh police has registered a case against unknown persons after it emerged that the Mewar Express had come to a sudden halt because the emergency chain was pulled.

The case has been registered under Sections 223 (escape from confinement due to negligence of a public servant) and 224 (resistance or obstruction by a person to his lawful apprehension) of the Indian Penal Code (IPC).

The accident occurred on Wednesday when the New Delhi-bound Goa Express rammed into the rear part of a stationary train, Mewar Express at 5.00 a.m. At least 22 persons were died and many others suffered injuries.

It was not clear how the two trains came to be on the same tracks. (ANI)