Air traffic controllers in Spain have launched four days of partial strikes that could affect thousands of flights in one of the most visited countries in the world.

The work stoppage called by the Union of Air Traffic Controllers (USCA) is scheduled to take place on Monday, Wednesday, Friday and Sunday between two blocks of time: 0800-1000 GMT and 1600-1800 GMT.

The move could disrupt flights to and from Spain at the peak of the tourist season. According to ENAIRE, Spain's air navigation regulator, the strike could cause major traffic disruptions and affect at least 5,355 flights in the world's third most visited country.

The latest strike comes as air traffic controllers are angry over sanctions imposed by ENAIRE against more than five dozen controllers in Barcelona after a wildcat strike which paralyzed Spanish air traffic in December 2010.

USCA has repeatedly called on ENAIRE to suspend the sanctions.

Meanwhile, sources say the Spanish ministry of public works has imposed minimum staffing services of 70 percent that could minimize the effect of the ongoing stoppage. The union says it will appeal the ministry's decision which it claims interferes with the right to strike.

Experts say the stoppage will have bad effects on the country's tourist industry. Tourism represents nearly 11 percent of the Spanish economy and 12 percent of jobs.

The developments come as Spain has been struggling to deal with its worst economic crisis since World War II.

Spain has had to enforce unpopular austerity measures in return for the loans and bailout funds from the International Monetary Fund (IMF) and the European Union (EU).

Spaniards have staged several protest rallies against the spending cuts, arguing that austerity measures have resulted in more job losses in recent years.

JR/KA/HMV