Volcanic activity on Italy’s southern island of Stromboli prompted authorities to raise the alert from level orange to red, the highest level, on Thursday. Residents were urged to follow the instructions of the local civil defence authorities on the small volcanic island north of Sicily. The National Institute of Geophysics and Volcanology (INGV) said increased volcanic activity had been detected at Mount Stromboli, an active volcano on the island. Lava and ash had poured out of the volcano and into the sea, INGV said. Only a few hundred people normally live on Stromboli. Many tourists travel …