ISTANBUL   Hezbollah confirmed Sunday evening that its senior commander, Ali Tabatabai, was killed in an Israeli airstrike in the Lebanese capital, Beirut. In a statement, Hezbollah mourned Tabatabai as “a key military commander.” The group also reported that four of its members were killed in the Israeli airstrike. The Israeli army said early Sunday that it had eliminated Tabatabai in a strike targeting Beirut’s southern suburb despite a ceasefire deal that has been in place since November