JERUSALEM (CNN) -- Israel has closed crossings between Israel and Gaza except for Erez crossing on Gaza's northern border, a military source said Wednesday.
The closing of the crossings came a day after four rockets were fired from Gaza into southern Israel by Islamic Jihad. The militant group said its members fired the rockets as revenge for the killing of one of the group's military commanders in the West Bank.
The rocket fire violated the truce that went into effect last week between Israel and Hamas leaders in Gaza. Israel said that under the conditions of the truce, the Hamas leadership in Gaza is responsible for all militant attacks on Israel -- not just those carried out by Hamas militants.
The cease-fire does not apply in the West Bank.
Mark Regev, a spokesman for the Israeli prime minister, called Tuesday's attacks "a grave violation" of the truce agreement.
A Hamas spokesman said Tuesday the group remains committed to the cease-fire despite the attacks.