At least 13 people died and almost 100 were injured in a train derailment in Mexico’s south-eastern Oaxaca region, the Mexican navy said.

The train, which was travelling between the Gulf of Mexico and the Pacific Ocean, was carrying 241 passengers and nine crew members.

A total of 98 were injured, of whom 36 were being treated in hospital, the navy said.

The train derailed as it rounded a bend near the town of Nizanda, officials said. Mexico’s Attorney General confirmed an investigation was under way.

Mexican President Claudia Sheinbaum said five of those injured were in a serious condition.

She said top level officials, including the secretary of the navy, were travelling to the site of the crash.

Photos from the site of the crash showed rescue workers helping passengers alight the train, which had fallen off the rail tracks and partly tilted over the side of a cliff.

The Interoceanic train, which connects the Pacific port of Salina Cruz with Coatzacoalcos on the Gulf Coast, had two locomotives and four passenger cars, the navy said. Mexico’s navy operates the country’s railway network.

The governor of Oaxaca, Salomón Jara Cruz, expressed “deep regret” over the accident in a statement and said state authorities were coordinating with federal agencies to assist those affected.

The Interoceanic rail link was inaugurated two years ago to boost the region’s economy, an initiative spearheaded by former President Andrés Manuel López Obrador.

Designed to modernise the rail link across the Isthmus of Tehuantepec, the Mexican government has sought to develop the area into a strategic trade corridor, expanding ports, railways and industrial infrastructure.

The train service is also part of a broader push to expand passenger and freight rail in southern Mexico and stimulate economic development in the region.