Gaza terrrorists fired 20 Kassam rockets and mortar shells at southern Israel on Sunday,  despite Israel's declaration of a unilateral cease-fire in the coastal territory on Saturday night.

On Sunday afternoon Hamas leaders also called a cease fire but gave Israel one week to withdraw all its forces from Gaza.

Also Sunday, the IDF began pulling out some of the troops who had been operating in Gaza over the past two weeks, as other troops manned positions throughout the Gaza Strip.

Infantry forces walked out of the Gaza Strip in columns, some soldiers had Israeli flags attached to their heavy back packs. Armoured vehicles and tanks were also seen pulling out from parts of the Gaza Strip.

During the day, a house in Ashdod suffered a direct hit from a Grad missile. Some  rockets hit  chicken coops in communites in southern Israel causing damage but no casualties. The rest of the rockets hit open areas near the southern Israeli town of Sderot, causing no casualties.

Following the salvoes fired into the South, Israel Air Force aircraft attacked rocket launchers in Gaza, the army said. "We hit the launcher that had fired rockets into Israel," an Israel Defense Forces spokesman said. According to reports earlier Sunday Gazan militants and IDF traded fire near Jabalya refugee camp in the northern Gaza Strip when a Hamas militant unit fired at the Israeli troops. IDF spokesman indicated the troops detected the source of fire and struck the militant unit. There were no casualties among the IDF soldiers.

One of Israel's stated goals in its offensive against Hamas in Gaza, code-named Operation Cast Lead, was to bring about the cessation of cross border rocket fire. At least seven Grad rockets were fired into southern Israel late Saturday, shortly after the cease-fire declaration. On Saturday night Prime Minister Ehud Olmert announced that Israel's security cabinet had voted in favor of the unilateral cease-fire in the Gaza Strip, which went into effect at 2 A.M. local time.