The cloud of volcanic ash from Iceland will cause fresh air traffic disruption in Spain from Monday afternoon although all its airports will remain open, the country's airports authority said. 'The evolution of the cloud of volcanic ash on Spanish airspace will require introducing restrictions in air traffic between 20,000 and 35,000 feet (6,000 metres and 10,600 metres) from 4:00pm (1400 GMT),' the authority, AENA, said in a statement. The restrictions will be place until at least 8:00pm (1800 GMT) and cause a 25-percent reduction in overflights in the regions around the southern city of Seville, the capital Madrid in the centre and Barcelona in the northeast. A spokeswoman for AENA said that air traffic should only be moderately disrupted, as transatlantic flights above 35,000 feet and national flights below 20,000 feet will be able to continue. In addition, she said some air corridors normally reserved for the military may be used for civil aviation. An extra air corridor should also be opened Monday by the air traffic control centre in the Canary Islands 'in order to help air traffic between the Americas and Europe.' AENA said all Spanish airports will remain open throughout the day, after 19 were closed on Saturday. Iceland's Eyjafjoell volcano erupted on April 14 and caused travel chaos worldwide, with airspace closed over many European nations for a week over fears the ash would damage aircraft engines with fatal results. It was the biggest aerial shutdown in Europe since World War II, with more than 100,000 flights cancelled affecting some eight million passengers. The airline industry said it lost about 2.5 billion euros (3.2 billion dollars). The volcano began fresh and intensive ash eruptions overnight Thursday, forcing the cancellation of hundreds more flights in Europe. 