Spain is observing three days of national mourning after a massive train crash that killed at least 40 people, according to officials.

MADRID – Two high-speed trains derailed on Sunday in southern Spain, the rail network operator said, and state-run television channel RTVE said five people had died, citing police sources.

Óscar Puente, Spain’s transport minister, told reporters that the first train to derail was only a few years old and that the section of the track where the accident occurred had been recently renovat...