The strike, called for Tuesday and Wednesday, will affect between 25% and 50% of all commuter and long-distance trains, said Spain's rail company, Renfe.

The train drivers union, known as Semaf, is demanding that the number of training hours for drivers be increased to 2,000, from the current 350, under a new training program, the daily El Mundo said.

A round of talks with officials of the Public Works Ministry, which controls Renfe, ended in disagreement Saturday. Another round was to be held later Monday.

Semaf Secretary-General Juan Jesus Garcia told Cadena SER radio the extra training hours were needed to ensure safety.

He said it was also a safeguard against companies that are looking to enter the sector in the coming years when Renfe's monopoly ends, training drivers as fast as possible.

There was no immediate comment from the Public Works Ministry.

The strike comes a week after pilots at Spanish airline Iberia went on strike for three days in search of guarantees that a new low-cost carrier created with Iberia capital will not cost the pilots jobs.

The strike, staged as the holiday season got under way, led to the cancelation of some 200 flights daily.