WASHINGTON — Iceland-based discount carrier WOW Air is adding new service from BWI Marshall Airport to Scotland this summer.

WOW Air is operating twice weekly flights from BWI Marshall to Edinburgh, via a stop at its hub in Reykjavik. The flights are on Tuesdays and Saturdays. Fares are as low as $189 each way.

After launching service with four weekly flights from BWI Marshall to Reykjavik in 2015, WOW Air began daily service earlier this year because of strong demand.

WOW offers service to other destinations from BWI Marshall through its Iceland hub, including flights to Paris and Amsterdam.

WOW Air, launched in 2011, now flies to 29 destinations across the U.S. and Europe, and says its passenger capacity will more than double this year to 1.9 million.

In June, it began its first Iceland to U.S. west coast service with flights to San Francisco International Airport and Los Angeles International Airport.

In addition to Baltimore, San Francisco and Los Angeles, WOW Air’s fourth U.S. airport is Boston.