The death toll from a train crash in India has risen to 13, with 39 injured, an official said on Monday, with investigators suspecting human error was the cause of the crash in the south-eastern state of Andhra Pradesh.

The accident occurred when the Visakhapatnam-Rayagada passenger train stopped on Sunday because of a break in an overhead cable and the Visakhapatnam-Palasa Express service rammed into it from the rear, derailing two carriages of the stationary train.

Nagalakshmi S., a senior government official in the district where the accident happened, told Reuters that more than 90 people were in the two coaches that got rammed by the second train and the toll of dead had risen to 13 with 39 people hurt.

The railway ministry said a preliminary investigation found that “human error” that led to “overshooting of signal” by the Visakhapatnam-Rayagada train.

An Andhra Pradesh fire services officer said early on Monday that no passengers were left at the site.

The accident came months after India’s state-run railway system suffered its worst crash in two decades when 292 people were killed.

Indian Railways, the fourth largest rain network in the world, is undergoing a $30 billion transformation with new train and modern stations in the pipeline.