Spanish train drivers began a three-day strike on Monday, demanding greater safety for their profession after two accidents claimed 47 lives last month, leaving thousands of passengers stranded.

The back-to-back disasters rocked the transportation sector and raised doubts about the safety of train travel in Spain, which boasts the world's second-largest high-speed network after China.

Unions called the February 9-11 strike accusing the authorities of ignoring warnings about the safety of infrastructure and failing to invest enough in the network.

Under minimum service requirements, 73 percent of long-distance services and 65 percent of regional trains are due to run, according to state railway company Renfe.

In suburban services, 75 percent of trains must run at peak hours and half of the normal service during the rest of the day.

Yet the disruption was clear to see at Madrid's Atocha, Spain's busiest train station, where thousands of passengers crowded the platforms during the morning rush hour with trains delayed or cancelled.

At Barcelona's main station Sants, fewer passengers were in the concourse than usual, with the strike following weeks of chaos on the northeastern Catalonia's ageing commuter network, used by hundreds of thousands of people.

A collision between two high-speed trains in the southern region of Andalusia on January 18 resulted in the death of 46 people -- one of Europe's deadliest such disasters this century.

Two days later, a commuter train in the Barcelona region ploughed into the rubble of a collapsed wall, killing the driver and injuring dozens. (AFP)