Six railway officials have been suspended for alleged negligence that led to Thursday's fatal train collision in the western Indian state of Gujarat.
Four coaches of the passenger train were derailed
The collision between a passenger train and a stationary goods train near the city of Baroda killed 17 people and injured 78, 34 seriously.
Two of the suspended workers are a signalman at the station and his assistant, a railway official said.
India has one of the world's largest rail networks but a poor safety record.
The chief public relations officer of Western railways, Shailendra Kumar, said the inquiry into the accident started on Saturday at the site at Samlaya station, 30km (18 miles) from Baroda.
The inquiry is by the commissioner of railways safety, who comes under the authority of the ministry of civil aviation.
A second railways spokesman, Kamal Kishore Dubey, told the Associated Press news agency that some of the suspended workers could be charged with negligent homicide, a crime that carries a jail term of up to six years.
"A faulty point lever setting sent the passenger train to the same track where the freight train was waiting for a signal to leave," said Mr Dubey.
The passenger train was en route from the northern holy city of Varanasi to Ahmedabad, Gujarat's main city, when it hit the freight train.
Four coaches of the passenger train and the engine of the freight train were derailed.
India has one of the largest rail networks in the world with 13 million people travelling each day.
There are about 300 accidents recorded each year.
In December, 36 people died after a head-on collision between two trains in the northern state of Punjab, leading to calls for the resignation of Railways Minister Laloo Prasad Yadav.
Mr Yadav's car was pelted with stones when he visited Thursday's crash site.