Palestinians inspect a destroyed compound of Hamas' Executive Force after an Israeli air strike early Tuesday in Gaza May 29, 2007. (Xinhua Photo)

    GAZA, May 29 (Xinhua) -- Israeli air and ground forces expanded Tuesday its crackdown operation against militants of the Islamic Resistance Movement (Hamas) in the Gaza Strip.

    More ground forces of the Israeli army have been sent into Palestinian controlled territories in northern and southern Gaza Strip, leaving the door opened for more escalation of the conflict with Hamas militants.

    Palestinian security sources said that for the first time in two weeks, Israel sent a ground force backed by more than 20 tanks and armored vehicles into an area southeast Gaza Strip, killing two Hamas militants.

    Palestinian medics at Abu Yosef al-Najjar in the town of Rafah in southern Gaza Strip said that three more civilians were moderately injured, including a 32-year-old woman during the Israeli incursion.

    The area that was stormed was not far from the commercial crossing of Sofa, east of Rafah town on the borders between Gaza and Israel, where witnessed the kidnapping of Israeli corporal Gilad Shalit almost one year ago.

    Witnesses said that after the Israeli soldiers killed the two Hamas militants, they stormed into several houses and detained two brothers of one of the two militants.

    Tuesdays' incursion into Rafah area is the first ground operation since the beginning of the Israeli operation on Hamas militants who fire rockets at southern Israel on May 17, said the Palestinian security officials.

    Before that, Israel has been hitting Hamas targets from air, killing 48 Palestinians.

    At predawn on Tuesday, Israeli warplanes have not left the air of Gaza, where it had targeted a building belongs to Hamas movement in the town of Beit Hanoun in northern Gaza Strip, but no injuries were reported.

    Following a meeting of the Israeli cabinet held on Sunday, Israeli Premier Ehud Olmert vowed to expand military actions on Gaza militants, whether militants halt or continue rockets attacks on Israel.

    Meanwhile, Hamas movement's armed wing spokesman vowed that attacks on Israel would continue "as long as Israel continues its aggression on our people and the men of resistance."