Ukraine said it struck a Russian air base on Saturday, while Russia continued to attack Ukraine with hundreds of drones overnight as part of a stepped-up bombing campaign that has dashed hopes for a breakthrough in efforts to end the more than 3-year-old war.

Hundreds of flights were delayed or canceled due to Ukrainian drone strikes on Saturday and overnight, according to Russia’s Transport Ministry.

With their dense mesh, the nets can tangle drone propellers. It’s a simple but effective countermeasure that reflects how low-tech means can blunt high-tech weapons in the war.