Rescue workers search the wreckage of a test TGV train that derailed and crashed in a canal outside Eckwersheim near Strasbourg.

AFP/Reuters
Strasbourg
Ten people were killed after a French high-speed train derailed during a test run yesterday, local officials said, announcing a rise in the death toll.
The train accident happened “because of excessive speed” at Eckwersheim in eastern France as technicians were on board for testing, said a top local official Dominique-Nicolas Jane.
However, police said the cause of the crash had not been determined.
A source close to the investigation said dozens of technicians were aboard.
The accident is the worst since the French TGV trains went into service in 1981.
French Environment Minister Segolene Royal said at the scene that a further five were unaccounted for.
A total of 49 technicians, but no paying passengers, were onboard when the accident happened during testing on one of the next generation of TGV high-speed trains due to go into service in Spring 2016, the local prefecture said.
The train ended up near a bridge in the water of a roughly 40m wide canal.
A police dive team, helicopters and tens of rescue vehicles were sent to the scene in response to the crash.  
The initial toll was put at “at least five dead”.
Pictures from a Reuters photographer at the scene showed the locomotive partly submerged in a canal alongside the tracks with other parts lying broken and detached in a field beside the track.