JERUSALEM (CNN) -- Israel reopened some of its border crossings with Gaza on Sunday, four days after it closed all but one passage because of Palestinian rocket attacks.
The Sufa and Nahal Oz crossings were open Sunday to allow for the passage of fuel, food and medical supplies.
Israel closed all but the Erez crossing on Gaza's northern border on Wednesday in response to rocket and mortar attacks from Gaza -- a violation of the fragile cease-fire between Israel and Hamas leaders.
Some of the rockets were fired by Islamic Jihad and Al Aqsa Martyrs Brigades, the militant wing of Palestinian Authority President Mahmoud Abbas' Fatah party.
Israel said that under the conditions of the truce, which went into effect June 19, the Hamas leadership in Gaza is responsible for all militant attacks on Israel and not just those carried out by Hamas militants.
In return, Israel agreed to halt raids inside Gaza and gradually ease its economic blockade if the truce holds.
Israel has said the truce is a first step toward a broader cease-fire agreement that must include the release of Cpl. Gilad Shalit, an Israeli soldier who was taken hostage two years ago by militants in Gaza.