Israeli planes attacked three bridges in central Gaza late Tuesday and early Wednesday, the military said, and Israeli tanks were on the move after a limited operation was approved, a response to a weekend Palestinian attack in which two soldiers were killed and a third captured.
Israeli military officials said Prime Minister Ehud Olmert approved a "limited operation" for southern Gaza, aimed at "terrorist infrastructure." The officials spoke on condition of anonymity because they were not authorized to talk to reporters.
Palestinian security forces said Israeli tanks were on the move near the Israeli village of Nahal Oz, a main Israeli staging area just outside Gaza, but they had not yet entered the territory.
In the Shajaiyeh neighborhood of Gaza City, not far from the border fence, armed militants took up positions across from the blaring headlights of Israeli vehicles, and Israeli attack helicopters hovered overhead. The roar of Israeli fighter planes reverberated throughout Gaza City.
The militants told residents to leave the area. They piled gasoline-soaked tires in the streets. Earlier, bulldozers blocked some of the main roads with piles of sand and dirt to try to slow down Israeli tanks.
One of the bridges targeted in airstrikes was in central Gaza, another near the town of Deir al-Balah and the third south of Gaza City, the Israeli military said and Palestinian security officials said. There were no reports of casualties.
The military said in a statement that the object of the attacks on the bridges was "to impair the ability of the terrorists to transfer the kidnapped soldier." Knocking down the bridges would cut Gaza in two, Palestinian security officials said.
Palestinian TV showed pictures of the first bridge hit, with fallen concrete blocks, twisted metal and protruding water pipes. Children walked in the wreckage.
The Israeli military said its warplanes attacked only two bridges, but one had two sections.
Israel has been massing troops and armor around Gaza since Sunday, when Palestinian militants tunneled under the border and attack an Israeli army post at a Gaza crossing, killing two soldiers and abducting a third.
Speaking Monday, Olmert pledged a harsh response for the attack and the abduction, saying it would be an extended military offensive against Palestinian militants in Gaza.
The beginning of the Israeli operation came against the background of no progress in locating the Israeli soldier. The militants holding him said they would release information only if Israel first freed minors and women among the Palestinian prisoners it is holding.
Olmert ruled out negotiations with the captors, and said release of prisoners is not on the agenda.
Three Islamic militant groups led by Hamas, which heads the Palestinian government, carried out the Sunday attack and were believed to be holding the soldier, Cpl. Gilad Shalit, 19, reports AP.