Madrid - Madrid's Barajas airport was Monday gradually returning to normal after delays and cancellations of flights affected thousands of passengers, the airport operator AENA said Monday.

Spain's main airline Iberia, however, was still struggling to deal with hundreds of stranded passengers.

The problems at the airport are largely due to an unofficial work to rule stoppage by Iberia pilots seeking pay hikes and better working conditions.

Many of the Barajas air controllers also called in sick on Friday, but AENA denied on Monday that they had wanted to protest eventual pay cuts.

The air controllers were back at work and the airport was again using all of its four runways - two of which had been temporarily out of operation - though fog was hampering air traffic, AENA said.

Cancellations of dozens of flights, as well as delays of up to 17 hours, have affected thousands of passengers, many of whom were expected to seek damages of up to
900 euros (1,250 dollars). (dpa)