The ill-fated Samjhauta Express, with a prescribed speed limit of 110 kmph, slowed down to 20 kmph near Dewana on February 18 before two blasts killed 68 people, strengthening the theory that the men who planted the bombs had got off the train.

After starting its journey from Old Delhi railway station at 10.50 pm on that day, the train "observed one speed restriction of 20 kmph between Badli and Holambi Kalan railway stations on the up line due to deep screening of the railway track," said the report of a statutory inquiry by the commissioner of railway safety.

The Commissioner of Railway Safety (Northern Circle) Bhupinder Singh, who conducted the probe, said the train ran through without stopping till Samalkha station and had an uneventful run. At the time of accident, its speed was 100 kmph.

The report said on the day of the blasts, there were no "permanent or temporary" speed restrictions on the up line in the Samalkha-Dewana section and at Old Delhi railway station.

The slowing of the train to 20 kmph would have helped anyone wanting to get off the moving train, sources said.

The preliminary report said the explosions in two coaches of the Samjhauta Express caused a fire and killed 68 passengers.

Though two men were arrested in Indore in connection with the blasts, security agencies are yet to make any breakthrough in their probe into the terrorist attack.

Investigators believe at least two men got off the train shortly before the blasts when they were challenged by RPF men.

The commissioner, in his provisional findings, said: "Having carefully considered the factual and circumstantial evidence so far available at my disposal, I am of the prima facie opinion that the unusual occurrence of fire in the coaches of 4001 Up Attari Special, while it was running through the station section of Diwana railway station of the Delhi-Ambala double line, took place due to explosion of bombs kept on the under racks near the doorways of the coaches.

These bombs on exploding caused a severe fire, which burnt the coaches vigorously. The high winds due to the high speed of the train (100 kmph) aggravated the speed of fire."