Eleven people were injured when two passenger trains collided near a station in the South African coastal city of Durban, emergency services said on Friday.

Police were investigating the cause of the crash, which involved two trains travelling in the same direction, Netcare 911 spokesman Chris Botha said.

Rescue workers had to free one woman trapped under the wreckage, who was taken to hospital, Botha said. Ten other people suffered mild to moderate injuries.

South Africa is in the midst of upgrading its creaking passenger rail network to improve public transport for millions of poor people without cars. About 90 percent of its train carriages date back to the 1950s, and long delays are common.

The government last year awarded a $5.8 billion contract to French transport group Alstom SA to supply 3,600 new carriages over ten years. The first batch is expected to be delivered in mid-2015.

Reporting by David Dolan. Editing by John Stonestreet.