GAZA CITY, Gaza Strip (AP) -- Israel resisted mounting international pressure Wednesday to suspend its devastating air offensive against militants in Hamas-ruled Gaza, sending more troops and tanks to the border as signs of an impending ground invasion multiplied. A long column of tanks and other army vehicles, two and three abreast, was strung out along an access road to Gaza. Dozens of tanks were parked in a rain-sodden field on the frontier.
Commanders were moving forward with preparations for a possible ground assault, said an Israeli defense official who spoke on condition of anonymity because of the sensitive nature of the information.
Earlier this week the government approved the callup of more than 9,000 reserves soldiers.
Heavy cloud cover that could encumber ground forces was expected to lift Thursday.
The diplomatic action was set in motion by Israel's aerial campaign, now in its fifth day, aimed at snuffing out militant rocket barrages that are striking ominously close to the Israeli heartland.
Gaza officials put the death toll at more than 390 dead and 1,600 wounded. Hamas says some 200 uniformed members of Hamas security forces have been killed, and the U.N. says at least 60 Palestinian civilians have died. Israeli defense officials say Hamas' top military and political leaders have gone underground and have not been touched.
Four Israelis have been killed by militant rocket fire, including three civilians.
The chief of Israel's internal security services, Yuval Diskin, told Cabinet ministers Wednesday that Hamas' ability to rule had been "badly impaired."
Weapons development facilities have been "completely wiped out" and a network of smuggling tunnels that has been Hamas' lifeline has been badly damaged, a participant in the meeting quoted Diskin as saying. He spoke on condition of anonymity because the meeting was closed to the media.
A senior military officer said Wednesday that Israeli warplanes had made some 500 sorties against Hamas targets in Gaza and attack helicopters flew hundreds more combat missions in five days of fighting.
The officer, who spoke on condition of anonymity in line with military regulations, claimed 95 percent of the intended targets were hit. He said the targets included Hamas command posts, some 130 missile launch sites and anyone who could be carrying a weapon. Also hit was Hamas' Islamic University, which he described as a weapons research facility.
He said all efforts were made to avoid civilian casualties, including calling residents on their phones to warn them their buildings were about to be hit.
The bombing onslaught has touched off protests across the Islamic world. In Iran on Wednesday, fundamentalist students asked their government to authorize volunteer suicide bombers to attack Israel. The Tehran government had no immediate response.
On Tuesday, France urged Israel to halt its operation for 48 hours. Israel Prime Minister Ehud Olmert discussed the idea with his defense and foreign ministers overnight, but the trio decided to pursue the punishing aerial campaign.
Calls for an immediate cease-fire have also come from the U.S., the European Union, the U.N. and Russia. President George W. Bush and Secretary of State Condoleezza Rice both called leaders in the Middle East on Tuesday to press for a durable solution.
White House officials said Bush talked with Olmert on Wednesday about finding ways to "end the violence" in the region and to voice concerns about civilian casualties in Gaza. Spokesman Gordon Johndroe said Olmert assured Bush that Israel is trying to limit such casualties as it goes after Hamas targets.
Israeli Cabinet ministers did not discuss the substance of a French cease-fire proposal at a meeting later Wednesday.
Olmert told ministers Israel embarked upon the offensive to radically transform the security situation in Israel's south and would not leave the job half done.
"If conditions ripen to the point that we assess they promise a safer existence in southern Israel, we will consider it. We're not they're yet," Olmert said, according to a meeting participant who spoke on condition of anonymity because the meeting was closed.
France said it was still trying to persuade Israel to suspend its attacks. "I hope there are no ground operations," French Foreign Minister Bernard Kouchner added.
Underlying the Israeli decision to keep fighting are the mightier weapons that Hamas has smuggled into Gaza through underground tunnels along the border with Egypt.
Previously militants had relied on crude homemade rockets that could fly just 12 miles to terrorize Israeli border communities. Now they are firing weapons manufactured in China and Iran that have dramatically expanded the militants' range and put more than a tenth of Israel's population in their sights, defense officials said.
More than 50 rockets and mortar shells were fired by late Wednesday afternoon, including rockets that hit in and around the major southern Israeli city of Beersheba, 22 miles from Gaza. One rocket struck an empty school.
Another landed in a small farming community about 20 miles southeast of Tel Aviv, the hub of Israel's biggest urban area. No serious casualties were reported.
School was canceled in large swaths of Israel's south because of the rocket threat. The 18,000 students at Ben-Gurion University in Beersheba, southern Israel's only university, were also told to stay home.
Early Wednesday, Israeli aircraft pounded smuggling tunnels under the Gaza-Egypt border in another attempt to sever the pipeline that keeps Hamas in power by supplying weapons, food and fuel. Israel and Egypt blockaded Gaza after Hamas violently seized control of the territory in June 2007, and have cracked open their borders only to let in limited amounts of humanitarian aid.
An Egyptian official, speaking on condition of anonymity because he wasn't authorized to speak to the media, said Israel has destroyed 120 tunnels since the aerial campaign began. According to conservative estimates, there were at least 200 tunnels before Israeli warplanes began striking.
In Gaza City, powerful bomb blasts sent high-rise apartment buildings swaying and showered streets with broken glass and pulverized concrete. The Israeli military said government buildings were hit, including an office of Gaza's Hamas prime minister, Ismail Haniyeh.
Israeli aircraft flattened a fifth mosque Wednesday, leaving only its minaret standing. Diskin, the Israeli security services chief, said militants have set up command centers in mosques.
Diskin said militants also were hiding at Gaza hospitals, some disguised as doctors and nurses. He said Hamas was trying to smuggle out some of its activists to Egypt through tunnels that were still passable.
Two Palestinian medics were killed and two others were wounded when an Israeli missile struck next to their ambulance east of Gaza City, Palestinians said. The Israeli military said it did not know of the incident.
Israeli navy ships also fired at Hamas positions along the coast.
Although Hamas leaders have been driven underground, spokesman Taher Nunu said the Gaza government was functioning and had met over the past few days.
"What our people want is clear: an immediate stop to all kinds of aggression, the end of the siege by all means, the opening of all border crossings, and international guarantees that the occupation will not renew this terrorist war again," Nunu said in a statement.
Israel fears that opening crossings with Gaza would allow Hamas - which remains officially committed to Israel's destruction - to strengthen its hold on the territory even further.
While rejecting France's proposed truce, Israel said it would allow 2,000 tons of food and medical supplies to enter Gaza on Wednesday, in addition to 4,000 tons the military says have been allowed in since the offensive began. Several dozen chronically ill and wounded Gazans were also authorized to enter Israel for treatment Wednesday, the military said.
The U.N. planned to resume food aid distribution Thursday, after halting it two weeks ago because of shortages caused by the blockade. Most of Gaza's 1.4 million people rely on U.N. food handouts. Britain and Indonesia also said they would send humanitarian relief.
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