Two people killed in Mexico theme park crash

At least two people have died after a speeding roller coaster car flipped over mid-ride at a Mexican amusement park.

When the last car on the ride derailed at La Feria theme park, two men 18 and 21 years old died from head injuries and other wounds, according to officials.

Another two were injured.

A theme park worker told local news outlet El Universal how she saw passengers being thrown from the car.

She said other riders hit their heads as the roller coaster advanced at high speed while dragging the flailing, final car.

Eyewitness Rosalba Rodriguez told reporters there was nothing unusual about the ride, which had completed a few loops, until she saw the last carriage fall.

Early investigations suggest a mechanical failure caused the car to come loose and plunge from a height of 33ft, said Ulises Lara Lopez, spokesman for the attorney general's office.

Authorities are treating the accident as a case of negligent homicide.

"This is now in the hands of prosecutors, and prosecutors have already taken the necessary steps for an investigation," an official told Reuters.

The fairground said it "deeply regrets the terrible accident".