The fighting in Gaza Strip escalated severely in May 2004 after several failed attempts to attack Israeli checkpoints such as Erez crossing and Karni crossing. On 2 May, Palestinian militants attacked and shot dead a pregnant woman and her four young daughters. Amnesty International classified it as a crime against humanity and stated that it "reiterates its call on all Palestinian armed groups to put an immediate end to the deliberate targeting of Israeli civilians, in Israel and in the Occupied Territories". Additionally, on 11 and 12 May, Palestinian militants destroyed two IDF M-113 APCs, killing 13 soldiers and mutilating their bodies. The IDF launched two raids to recover the bodies, killing 20–40 Palestinians and greatly damaging structures in the Zaitoun neighbourhood in Gaza and in south-west Rafah.