UNITED NATIONS — Top Iranian officials have increased their verbal attacks and threats against Israel in recent days, in a pattern seen by Iran-watchers in Jerusalem as a possible precursor of a terrorist attack against Israel or other Jewish targets around the world.

Secretary-General Ban said yesterday that the use of terms like “dirty microbe” and “savage animal” by President Ahmadinejad in reference to Israel was “unacceptable.” Earlier this week, Iran’s Revolutionary Guards commander, Mohammad Ali Jafari, predicted the “destruction of the cancerous existence of Israel,” and the Iranian foreign minister, Manouchehr Mottaki, said Israel has no “legitimacy” in the region.

Beyond possibly preparing the ground for retaliation for the killing of a Hezbollah leader, Imad Mughniyeh, according to Israeli officials, Iran’s rhetorical escalation may be intended to divert attention from an upcoming report by the U.N. nuclear watchdog about Tehran’s nuclear activity. The International Atomic Energy Agency’s report, to be issued as early as today or tomorrow, is expected to be followed by the imposition of a new round of mild sanctions by the Security Council on Tehran’s mullahs, as proposed by top council powers, including Iran allies Russia and China.

Iran has said Israel was behind last week’s Mughniyeh assassination in Damascus. Israeli officials have not taken responsibility for the killing, but “I have no doubt the Iranians will try to retaliate and get a big hit soon, here or abroad, in a manner intended to surprise and shock,” a Jerusalem source familiar with Israeli intelligence on Iran said yesterday, speaking on the phone on condition of anonymity.

The recent threats by Iranian officials “are not just words. They derive from a principled position, which is that Israel should not exist,” a former Israeli deputy defense minister, Ephraim Sneh, said. “We have to be alert, and to be alert everywhere.”

Israel’s U.N. ambassador, Dan Gillerman, called a meeting yesterday with Mr. Ban, to underline Jerusalem’s concerns about Mr. Ahmadinejad’s latest comments. “It is unacceptable and undesirable for a head of state of a member state of the United Nations to use such kind of language against any other member state,” Mr. Ban told The New York Sun after the meeting with Mr. Gillerman.

The Israelis “assassinate pure and pious people and then they celebrate it, like what happened to the son of Lebanon who had stood against the savage onslaught of the Zionists and broke the Zionists’ horns,” Mr. Ahmadinejad told a crowd during yesterday’s nationally televised rally in Bandar Abbas, Iran, referring to Mughniyeh. “World powers have created a black and dirty microbe named the Zionist regime and have unleashed it like a savage animal on the nations of the region,” he said. To counter Israel’s complaints, Iran’s U.N. ambassador, Mohammad Khazaee, wrote a letter to Mr. Ban and the Security Council’s president, Ricardo Alberto Arias of Panama, citing comments by Prime Minister Olmert and other Israeli officials about reserving the military option to stop Iran from getting a nuclear bomb. It is “preposterous” for Israel, with its “shocking” record, to complain about Iran, Mr. Khazaee wrote.

Mr. Gillerman said the “pathetic” Iranian complaint was not analogous to his own. “I suggest that everyone will listen very carefully to what is said in Tehran,” he said. “The world — and the Jewish people specifically — paid a very high price for ignoring such threats in the past.”

The report by the IAEA director, Mohamed ElBaradei, is unlikely to be damaging to Iran’s case, according to a diplomat familiar with the agency’s work. New detailed data on Iran’s nuclear activity — including new satellite images — which reportedly were passed on to the IAEA recently by a dissident group, the National Council of Resistance of Iran, is unlikely to be included in Mr. ElBaradei’s current report, the diplomat said, speaking on condition of anonymity.