JERUSALEM — Israeli security forces are importing horses, water cannons, tear-gas launchers and a nauseating noise machine to control crowds if they become violent at Palestinian protests planned next month to support their bid for U.N. endorsement of statehood. Israel hopes the measures will avoid casualties among demonstrators.

Palestinian authorities have made plans that aim to keep the protests peaceful and avoid confrontations with Israelis. Israel fears that a single incident — a Palestinian killing an Israeli with a firebomb or gunshot, or an Israeli soldier killing a Palestinian during a riot — could trigger a flood of violence when large crowds are already out protesting.

Palestinians are planning mass demonstrations across the West Bank and abroad to coincide with the September U.N. General Assembly session, which the Palestinians hope will give official endorsement for their state. The statehood initiative reflects frustration with long stalled Israeli-Palestinian peace negotiations.

Police have doubled the size of their riot control forces to more than 2,000, according to an internal police newsletter obtained by The Associated Press.

"The police hope to avoid casualties in the event of (U.N. endorsement of) Palestinian independence," Nissim Mor, commander of the police operations branch, wrote in the newsletter.

The police newsletter spelled out the equipment police are planning to use, including a machine that generates sound waves that cause nausea.

Police have ordered such a machine, called "the scream," the newsletter said, adding that they are also acquiring "the skunk" — a device that sprays a foul-smelling fluid to subdue unruly crowds.

Also, 15 horses arrived this week from Belgium and two additional water cannons are on order, it said.

Israel has supplies of tear-gas grenades and launchers and is ordering more, military officials said. Soldiers have used rubber-coated steel bullets in past confrontations that have killed Palestinians.

The feverish preparations reflect painful lessons from Israel's botched and bloody confrontation in May when thousands of Palestinians stormed across the Syrian border and Israeli solders fatally shot more than a dozen.

Israel absorbed stiff international criticism for the bloodshed, and officials admitted later that the military was caught unprepared and did not have proper crowd control means.

Police spokesman Micky Rosenfeld said preparations have been under way for several weeks, stressing non-lethal methods the police are used to employing.

A section of southern Israel has been turned into a "September training camp" to train soldiers on how to handle violent scenarios without causing fatalities, according to Israeli officials who spoke on condition of anonymity because of the sensitivity of the issue.

The officials also told the AP that Israeli security is working with top Palestinian commanders to coordinate activities aimed at avoiding casualties. Palestinian officials would not comment on that.

Riyad Mansour, the Palestinian U.N. representative, said if hundreds of thousands of Palestinians rally peacefully in September under the slogan "The People Want the End of Occupation. The People Want Independence," it should affect "the dynamics of what will happen in the United Nations, whether in the Security Council or in the General Assembly."

He said close to 130 nations have already recognized Palestine as an independent state, which is more than two-thirds of the membership of the U.N. General Assembly. But he said the United States at "this moment" would veto U.N. membership for Palestine in the Security Council, even though it has aided the Palestinians in building their institutions.

With such strong support in the 193-member world body, Mansour asked in the interview on France 24 TV, "What would be the argument of any member state in the Security Council of depriving us of our natural, historic and legal right to join the community of nations as a new member state?"

The U.S., Israel and many European nations maintain that a Palestinian state must emerge from Israeli-Palestinian negotiations, which have been stalled for almost a year.

Even if U.N. membership is thwarted, Mansour said, the Palestinians have the votes in the General Assembly, where there are no vetoes, to be recognized as a state and to change their status at the United Nations from an observer to a nonmember state, like the Vatican. "That at least would resolve the issue of the existence of the state," he said.