The Erez crossing to the Gaza Strip will be opened on Sunday for injured Palestinians to enter Israel for medical treatment, IDF spokesman Peter Lerner said Friday. Over 400 Palestinians have been killed and some 1,700 wounded since the beginning of IDF Operation Cast Lead last Saturday. The offensive targets Hamas in the Strip. Earlier in the week, a seven-year-old Gaza boy who suffered a serious head wound in IAF air strikes was rushed through the Erez Crossing and taken to Schneider Children's Medical Center in Petah Tikva. The boy, whose transfer was facilitated by the Peres Peace Center, was in critical condition in the intensive care unit on Wednesday night. Meanwhile, Physicians for Human Rights-Israel, which favors the transfer of Gaza civilians hurt in the bombings, said the Palestinian Authority is unwilling to pay for their medical care in Israel because Hamas is responsible. The PHR-Israel has urged the PA to facilitate such transfers immediately and argue later about who would finance the treatment to save their lives. Three other wounded children were also transferred via the Erez Crossing, with help from UNRWA. Twenty Gazans suffering from serious illnesses unrelated to the fighting were allowed through on Wednesday for treatment in Israeli hospitals.