The death toll in a train crash in southeastern Democratic Republic of Congo has reached 75, officials said Sunday, as experts began looking at the causes of the crash.

Officials on Saturday gave a toll of 60 men, women and children killed in the accident, which happened on Thursday night when a freight service train derailed.

The new toll came from Fabien Mutomb, head of the state railway company SNCC, after he visited the site with a team assembled to investigate the disaster.

Of the 125 people injured 28 were in a critical condition, said the communications ministry.

Rail officials have not said what caused the crash, but investigators will be looking at the condition of the track.

The province’s interior minister, Deodat Kapenda, who was among those who visited the site, said in a statement Sunday evening that the accident appeared to have been caused by a sudden loss of traction.

Mutomb, in his statement, said one possible cause might have been the overloading of the train because of people illegally hitching a ride on it.

“Measures will be taken to ensure that this kind of incident does not happen again,” and those responsible would be punished, he added.

– Possible causes –

On Saturday, the SNCC’s director of infrastructure Marc Manyonga Ndambo told AFP the train had been made up of 15 wagons, 12 of them empty.

It had been coming from Luena in a neighbouring province destined for the mining town of Tenke, close to Kolwezi, when the accident happened.

It derailed at 11:50 pm (2150 GMT) on Thursday at the village of Buyofwe, about 200 kilometres (125 miles) from Kolwezi, seven of its wagons plunging into ravines.

It was carrying several hundred stowaways at the time, said Manyonga Ndambo, speaking by phone from Lubumbashi.

On Sunday, he said the track had been cleared but the wagons involved in the crash still had to be towed away.

People regularly jump rides on freight trains to travel across the vast country because of the lack of passenger trains and the difficulties of travelling by road.

Train derailments are common in the DRC, as are shipwrecks of overloaded boats on the country’s lakes and rivers.

According to a database maintained by AFP, last week’s accident was the deadliest in the world over the last two years, and the third worst accident in Africa over the last 10.

The last accident in DR Congo of this kind happened in 2014, when a good train on which several hundred people were travelling derailed at Katongola, in the southeast region of Kataga, killing 136 people.

Mutomb is expected back in Kinshasa on Monday to report on the extent of the damage, the communications ministry said.