Banai participated in a long list of combat missions including the preparations and attack on the British high commissioner in Palestine, Sir Harold MacMichael. This attack was claimed to be retaliation for the Struma disaster. He also took part in the assassination of Thomas Wilkin, the head of the Criminal Investigation Department (CID) Jewish Affairs Bureau. Wilkin was assassinated for his involvement in the killing of Abraham Stern. In his memoirs, Banai recalled that the order to assassinate Wilkin came directly from Yitzhak Shamir, the head of Lehi who eventually became the Prime Minister of Israel.