The Israeli military said troops only opened fire after encountering unexpected resistance from the activists. Activists attacked troops with knives and iron rods, and opened fire with two pistols seized from the forces.
A total of five soldiers were wounded, two seriously, including at least one hit by live fire, the army said. Two of the dead activists had fired at soldiers with pistols, the army said.
"They planned this attack," said Israeli military spokeswoman Lt. Col. Avital Leibovitch. "Our soldiers were injured from these knives and sharp metal objects ... as well as from live fire."
"Those crafty humanitarians! It was all their fault! They lured us right into a trap! They beckoned us to approach and to storm their ships like the Jewish animals we are! And we, we were waving guns around, see, minding our own business! And they sprung their trap! They attacked us with rods and sticks! So we had to act like the Jewish animals we are and open fire on people bringing food!"