Although Palestinian groups committed to a ceasefire
during talks with Prime Minister Ismail Haniyeh and President Mahmoud Abbas, Palestinian Authority officials fear that small groups could breach the ceasefire out of political considerations aimed at provoking Israel to renew its military incursions into the Gaza Strip.
At 7 am on Sunday, an hour after the ceasefire went into effect, a Qassam rocket was fired at Sderot.
Two Qassam rockets were fired into Israel an hour later.
The Islamic Jihad claimed responsibility for the attack as Palestinian Authority officials said the group's leadership is divided over the ceasefire.
Hamas also took responsibility for firing rockets into Israel during the ceasefire, charging that Israeli troops remain in Gaza.
Abbas and Haniyeh hope to convince all groups to abide by the ceasefire, including the Abu-Rish Brigades, which declared it will carry on launching attacks against Israel.
Abu-Rish is affiliated with Fatah but some of its divisions have been working closely with Hamas and the Popular Resistance Committee.
Although the Palestinian Ministry of the Interior said the Abou El-Rish Brigades will abide by the ceasefire, a senior official rejected the declaration.
Representatives from all factions will meet later on Sunday to discuss the ceasefire, a meeting the Palestinian Authority hopes will yield a commitment to a lull with Israel.