By Laila Bassam, Nidal al-Mughrabi and Arafat Barbakh BEIRUT/CAIRO/GAZA (Reuters) -Israel killed Hamas deputy leader Saleh al-Arouri in a drone strike in Lebanon’s capital Beirut on Tuesday, Lebanese and Palestinian security sources said, as its tanks and warplanes pummelled Gaza in further “high-intensity” warfare against the Islamist militant group in the enclave. Arouri, 57, was the first senior Hamas political leader to be assassinated since Israel launched a shattering air and ground offensive against Gaza’s Hamas rulers almost three months ago after a shock Hamas militant rampage into Is…