The lives lost in Japan's train derailment accident have risen to 104 as of Thursday, and questioning of the railway operators' obsession with punctuality is growing.

Rescue workers recovered seven bodies, possibly including the driver, on Thursday from the wreckage of the first car which crashed into a nearby building after the derailment, Japanese media reported.

The transport ministry has ordered West Japan Railway Co., the operator of the train service, to work out safety improvement measures including retraining drivers.

Speeding is now suspected to be the leading reason for the accident, the deadliest in about 40 years in Japan.

A growing number of people are calling on authorities to reviewrailway companies' unduly requirement on punctuality, a decades-old virtue for the nation's railway system.

The 23-year-old driver, only 11 month on the job, overshot the last station by about 40 meters and had to back up. When derailing,the train was running at more than 100 kilometers per hour at the curve where the speed limit is 70 kph. It is widely regarded that the driver might be under pressure and try to make up for the one and a half minutes delay. A train driven by him was two minutes behind schedule on April 11, the Yomiuri Shimbun reported.

The seven-car commuter train with about 580 passengers aboard hurtled off the tracks shortly after morning rush hour in Amagasaki, Hyogo Prefecture. The injured were at more than 450.

The railway accident is the worst in Japan since 161 people died in November 1963 in a triple collision on the in Yokohama Prefecture. Japan's worst-ever railway accident which occurred in February 1947 when a train got derailed and turned over in SaitamaPrefecture, killing 187 people.