India’s federal police havearrested three railway employees on Friday in connection withthe country’s deadliest train crash in two decades that killed292 people last month, a person with direct knowledge of thematter said.

The arrests were made under Indian penal code sectionsrelated to culpable homicide, the source added, requestinganonymity as they were not authorised to speak to the media.

The June 2 crash at Bahanaga Bazar station, in the easternIndian state of Odisha, also injured more than 1,000 people.

It is India’s worst train crash in more than two decades.

The accident happened when a passenger train hit astationary freight train, jumped off the tracks and hit anotherpassenger train coming from the opposite direction.

The federal police Central Bureau of Investigation (CBI) hadlaunched an investigation after registering a case of criminalnegligence.

Spokespersons for the Indian Railways and the CBI did notimmediately respond to Reuters’ requests for comment.

Reuters reported earlier this week that workers repairing arail-road barrier had made faulty connections in the automatedsignalling system on the network.

In a report seen by Reuters the Commission of Railway Safety(CRS) investigators said the first collision occurred due tomodifications made to the signalling circuit to fix frequentproblems at a nearby rail-road barrier.

Local railway staff did not have a standard circuit diagramwhich led to a faulty connection in the signalling system whenthey tried to take the boom-barrier circuit offline for repair,it said. The malfunctioning system directed the passenger trainonto the path of the freight train, it said.

Indian Railways, the fourth largest train network in theworld, is a state monopoly run by the Railway Board. The boardreports to the Railways Ministry.

The rail network is undergoing a $30 billion transformationwith new trains and modern stations under Prime MinisterNarendra Modi’s push to boost infrastructure and connectivity.