Mount Etna, Europe’s most active volcano, has started erupting, spewing ash on Catania, eastern Sicily’s largest city, and forcing a suspension of flights at that city’s airport. Italy’s National Institute of Geophysics and Volcanology, or INGV, which closely monitors Etna with instrumentation on the slopes, noted that cloud cover on a rainy day was impeding views of the eruption, which often serves up a spectacular display of flaming lava during the volcano’s not infrequent eruptions. The institute said that ash had fallen on Catania and at least one town on Mount Etna’s inhabited slopes. No injures were reported.