ATHENS—Wildfires burned in regions across southern Europe on Monday, fuelled by hot weather and strong winds, as some northern countries cleaned up after a weekend of torrential rain and flooding. In Greece, Prime Minister Kyriakos Mitsotakis said firefighters had battled around 50 fires during the past 24 hours and it was likely there would be more with meteorologists warning that a further heatwave was in prospect. “I want to emphasize that August remains a difficult month,” he said. “That is why it is important for all of us, all state services, to be on absolute alert until the firefighting period is formally over.” Fire service officials said negligence on farms and construction sites had been behind several incidents, many of which were in the southern Peloponnese region. No casualties were reported. Conditions in southern Europe were in sharp contrast to the torrential rainstorms that lashed northern countries from Austria to …