Two people have died and others have been injured after a rollercoaster derailed at La Feria Chapultepec Magico theme park in Mexico City, Mexico.

According to the Mexico City attorney general's office, the victims were men aged 18 and 21, who died from head and other injuries after the last car on the Quimera rollercoaster derailed and flipped over, falling from a height of ten metres (33ft). Preliminary investigations indicate a mechanical failure, said the attorney general's office.

Two women, aged 27 and 35, are reported to have been injured in the crash and are in a stable condition in hospital.

Local government officials have said an investigation will be undertaken "quickly and transparently", while media reports state that authorities are treating the incident as "negligent homicide".

The Quimera ride was manufactured by Schwarzkopf and designed by Werner Stengel. It was the world's first rollercoaster with three vertical loops, and has been in use at La Feria since 2007.

It was first purchased by showman Rudolf Barth in 1984 and spent 12 years on the German fair circuit as Dreier Looping. Subsequently, it went to Sunway Lagoon for two years as Triple Loop Coaster, before five years as Magnum Force at the Flamingo Land resort in the UK.

Schwarzkopf Industries – which closed in the late 1980s – has built almost 150 rollercoasters around the world, with many still in service today.

The La Feria theme park remains closed following the accident on 28 September.