Israel unleashed a wave of airstrikes in Gaza on Friday, killing at least 10 people, including a senior militant, and wounding dozens, according to Palestinian officials. Israel said it was targeting the Islamic Jihad militant group in response to an “imminent threat” following the arrest of another senior militant in the occupied West Bank earlier this week. Palestinian militants launched a barrage of rockets hours later as air raid sirens wailed in central and southern Israe. Islamic Jihad claimed to have fired 100 rockets. Israel and Gaza’s militant Hamas rulers have fought four wars and se…