Investigations are under way into what caused a train to derail in south-eastern Spain on Saturday evening, killing two people.

Twenty-four people were injured, four of them critically, when the train left the tracks near the town of Tobarra, in the Albacete area at about 1900 (1800 GMT).

About 220 passengers were aboard the train, which was travelling between Madrid and Cartagena, when the incident happened, officials from the Spanish state rail company Renfe said.

Spanish Prime Minister Jose Maria Aznar and Infrastructure Minister Francisco Alvarez Cascos are due to visit the site of the crash later on Sunday.

Some reports said passengers heard a loud bang and then felt carriages bouncing.

The engine, a freight wagon and the first carriage left the rails.

About 30 people were travelling in the passenger carriage that overturned, a spokesman for Renfe said.

Some of the injured had to be freed from the wreckage by emergency workers.

Passengers who were not harmed in the incident were taken to their destination by bus.