Mike Davis in Buda's Wagon, p. 27-28 writes:
If the Haganah thought the February 28 Haifa garage massacre would put the other side out of action, they were cruelly mistaken. Although the window of opportunity for car-bombings - the possibility of passing, even in disguise, from one zone to another - was rapidly closing as Palestinians and Jews braced for all-out conventional warfare, the chief Palestinian bombmaker Fawzi Kutub would send the Haganah one more gift. On March 11, 1948, the official limousine of the American consul general, flying the Stars and Stripes and driven by the usual chauffeur, was admitted to the courtyard of the heavily guarded compound in Jerusalem which housed the Jewish national institutions. Although the Haganah general staff had warning that an assault on the Jewish Agency offices was imminent, there was no inkling that the attacker would be a US citizen, much less a past collaborator with Zionist intelligence.Events involving Anton Da’ud Kamilyo:
But the consul general's Armenian-American driver, Anton Da'ud Kamilyo, also known as Abu Yussef was actually a Palestinian double agent. Hidden in the trunk of the green Ford were 220 pounds of TNT: this was more than enough, in the estimate of Kutub, to wipe out the entire general staff of the Haganah. Da'ud parked the consulate car in front of the Agency headquarters and fled in a taxi, but a security official named Chaim Gur-Arieh became suspicious of wires dangling from the trunk, and he moved the car. "As Gur-Arieh set the brake, the charge exploded. The wall outside the lower two stories was destroyed and part of the wing collapsed. Flames engulfed the building." The chairman of the Jewish National Fund, Leib Yaffe, and 6 colleagues were killed, and almost 100 were injured. As Ben-Gurion had so rightly feared, the car bomb had been returned to sender - with interest.