(Reuters) - War with Iran would probably turn into a month-long conflict on various fronts with missile strikes on Israeli cities and some 500 dead, Israel's civil defense minister said in an interview published on Wednesday.

"There is no room for hysteria. Israel's home front is prepared as never before," Matan Vilnai, a former general who is about to leave his cabinet post to become ambassador to China, told the Maariv daily.

The interview coincided with Israeli media reports over the past week suggesting that Israel might attack Iran's nuclear facilities before the U.S. presidential election in November.

U.S. Defense Secretary Leon Panetta said on Tuesday that Washington does not believe Israel has made a decision on whether to strike.

"I don't want to be dragged into the debate," Vilnai said, when asked if Israel should go to war against Iran. "But the United States is our greatest friend and we will always have to coordinate such moves with it."

Echoing an assessment already voiced by Defence Minister Ehud Barak, Vilnai was quoted as saying hundreds of missiles could hit Israeli cities daily and kill some 500 people in a war with Iran, which has promised strong retaliation if attacked.

"There might be fewer dead, or more, perhaps ... but this is the scenario for which we are preparing, in accordance with the best expert advice," Vilnai said.

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