Railways are finding themselves in a tight spot for being unable to explain the cause behind the derailment of Mandore Express near Jaipur, which claimed seven lives, as the track there was newly laid and inspected recently.

"We had even inspected the track using the latest technology very recently and chances of derailment was very remote," said a senior official as top brass of the railways, including DRMs, were today pulled up for reportedly being "lenient about the safety aspect".

Not ruling out human error as a possible reason for the derailment, railway sources said the driver was speeding at 105 kmph and the Commissioner of Railway Safety (CRS) is examining whether he was over speeding.

He (driver) has not been given a clean chit yet, they said.

Fracture of rail tracks due to changing weather is also being looked into, they said.

The Delhi-bound Mandore Express derailed about 40km from Jaipur early Saturday morning, with the track piercing into one of the AC coaches.