At least 32 people were killed and 91 injured when two trains collided in central Egypt on Friday, health ministry officials said.

“Unknown individuals” triggered the emergency brakes on one of the trains causing it to stop, the rail authority said. The second train, which was travelling in the same direction, crashed into the first from behind, it added.

Pictures showed train carriages derailed, several of them badly damaged, above a channel of water, as crowds looked on.

The public prosecutor’s office said it had ordered an investigation into the crash which took place close to the Nile-side town of Tahta, about 365 km (230 miles) south of Cairo.

Egypt’s President Abdel Fattah al-Sisi mourned the victims of the crash in a statement posted on his official social media and said those responsible would be punished.

Sisi also told Prime Minister Mostafa Madbouly to head to the site of the crash with the ministers of health and social solidarity, state television reported.

The health ministry said 32 people had died and dozens of ambulances were taking casualties to local hospitals. A health ministry spokesman said 91 people were injured.

Egypt has one of the oldest and largest rail networks in the region and accidents involving casualties are common.

In the country’s worst train disaster, a fire tore through seven carriages of an overcrowded passenger train in 2002, killing at least 360 people.