DALLAS (AP) — Southwest Airlines canceled hundreds more flights Monday following a weekend of major service disruptions. By midmorning Monday, Southwest had canceled about 360 flights and more than 600 others were delayed. The Dallas-based airline blamed air traffic control issues and bad weather for weekend “operational challenges” that resulted in 1,900 canceled flights on Saturday and Sunday. The Federal Aviation Administration took the unusual step of pushing back against Southwest’s explanation. Southwest Airlines was the only airline to report such a large percentage of canceled and delayed flights over the weekend.