A leading Islamic cleric in the Gaza Strip has ruled it a sin to violate the recent cease-fire between Israel and the Hamas militant group that controls the Palestinian territory.

The fatwa, or religious edict, issued by Suleiman al-Daya late Saturday accords a religious legitimacy to the truce and could justify any act by Gaza's government to enforce it.

"Honoring the truce, which was sponsored by our Egyptian brethren, is the duty of each and every one of us. Violating it shall constitute a sin," the fatwa read.

The Wednesday truce put an end to an eight-day Israeli offensive against Gaza militants who fired rockets into Israel. The agreement remains fragile because details beyond the initial cease-fire have not yet been worked out.

Al-Daya's edict came after Moussa Abu Marzouk, a top official in the Strip's ruling Hamas, said that the group would not stop arming itself because only a strong arsenal, not negotiations, can extract concessions from Israel.

Hamas demands that Israel and Egypt lift all restrictions on the movement of goods and people in and out of the Palestinian territory, which has been buckling under a border blockade since the Islamists seized the territory in 2007. The restrictions have been eased somewhat in recent years, but not enough to allow Gaza's battered economy to develop.

Abu Marzouk said Saturday that the group would not disarm, arguing that recent Palestinian history has shown that negotiations with Israel lead nowhere unless backed by force.

"There is no way to relinquish weapons," Abu Marzouk said in his office on the outskirts of Cairo. "These weapons protected us and there is no way to stop obtaining and manufacturing them."

Hamas' founding charter calls for Israel's destruction, but leaders of the group have also said they are ready for a long-term cease-fire with the Jewish state.

Open gallery view Armed Hamas militants in Gaza. Credit: Reuters