Pedro Sanchez pledged to keep relatives informed as they provided DNA samples to help police identify victims. (EPA Images pic)URDA: Prime Minister Pedro Sanchez on Friday said Spain was working "tirelessly" to identify the 69 victims of this week's high-speed train collision as the anguish of distraught relatives grows.

Wednesday's crash in the central region of Castilla-La Mancha was Spain's second such disaster this year and one of Europe's deadliest rail accidents this century.

Relatives of the victims have endured an agonising wait for news as rescue crews sift through the wreckage of tangled metal and bodies are examined in morgues.

"All branches of the state are working tirelessly... to try to give and provide the most information possible, as soon as possible, reliably, to the relatives of the victims," Sanchez said in the central city of Toledo, where most of the bodies have been taken.