BRUSSELS, July 25 (Xinhua) -- A two-day strike starting Wednesday by Ryanair's cabin crew in Belgium's Brussels and Charleroi airports has led to flight cancellations, affecting tens of thousands of travelers.

The strike is expected to affect around 23,500 people, reported the Belgian newspaper Le Soir.

On Wednesday afternoon, Brussels Airport said the on-going strike has already disrupted 4,900 passengers flying to and from Brussels. According to the airport, 13 flights on arrival and 13 flights on departure were canceled.

At Charleroi Airport, there are some 9,500 people affected by cancellations, according to Le Soir.

Meanwhile, the right to additional financial compensation, which ranges from 250 to 600 euros depending on the distance, will "not be automatically granted", and must be decided "on a case-by-case basis under the control of the national legal authorities," said a spokesman of the European Commission.

The Belgian non-profit organization Test-Achats said it would undertake legal actions if passengers are not given appropriate compensation for their losses.