A long-distance train carrying around 500 passengers on board derailed on Tuesday near near Pourtalé station, some 30 kilometres from Olavarría, leaving at least 21 people slightly injured, authorities said.
"We received at our Municipal Hospital,17 people with minor injuries. Three of them with fractures, none of them seriously injured. All are being treated by our health team," tweeted Ezequiel Galli, the mayor of Olavarría, a city in Buenos Aires Province near the scene of the accident.
Local health officials said that most were discharged during the same, with three individuals suffering fractures and one person was hospitalised with a "traumatic brain injury."
The train was heading from Plaza Constitución station in the capital, Buenos Aires, to the city of Bahía Blanca. The accident occurred at 05.20am local time "for reasons that are unknown and are being investigated," said state-owned Trenes Argentinos said on Twitter, which clarified that the laying of the tracks is operated by the private freight company FerroExpreso Pampeano.
"They derailed the first five cars," Galli said.
One of the cars was left overturned on the ground.
According to reports, the train was already running two hours late.