DAKAR, Senegal — The president of the Palestinian Authority, Mahmoud Abbas, accused Israel of implementing policies he claimed were part of an “ethnic cleansing” campaign in the Palestinian Arab areas of Jerusalem.

Speaking at a summit of Islamic countries in the Senegalese capital, Dakar, Mr. Abbas said Israel had carried out policies designed to force Palestinian Arabs out of the city.

“Our people in Jerusalem are under an ethnic cleansing campaign,” Mr. Abbas said in a speech. “They are suffering from a series of decisions like tax hikes and construction prohibitions.”

Mr. Abbas said Palestinian Arabs “are facing a campaign of annihilation” by the Israeli state.

In Washington, a State Department spokesman, Sean McCormack, said that “we would not use that term to describe the situation. I think it’s probably an example of some overheated political rhetoric.”

“We would urge both sides, both the Israelis and the Palestinians, to keep their focus on the political process,” Mr. McCormack said.

At the summit of the 57-member Organization of the Islamic Conference, the world’s largest Muslim organization, Mr. Abbas appealed to Muslim leaders for support during a difficult junction in the Middle East peace process.

President Abdoulaye Wade of Senegal, who is chairing the OIC, condemned Israeli attacks but also called for unity among feuding Palestinian Arab factions.

American-backed peace talks between Israel and the Palestinian Arabs have been strained by a recent surge in fighting. Today, the militant Islamic Jihad group in Gaza fired dozens of rockets at southern Israel after Israeli undercover forces killed one of its West Bank leaders.

Mr. Abbas said Palestinian Arabs expect Israel to meet “commitments to put an end to its aggressions and settlements expansion … Yet what is taking place on the ground today is totally in violation of that.”

Palestinian Arabs are split between the moderate government led by Mr. Abbas in the West Bank and the militant Hamas group that has ruled Gaza since seizing the coastal strip by force last year.

“I should like to tell our brothers and sisters of Palestine that your unity is the first priority of success … Please unite,” Mr. Wade said. He also called Israel “an occupying power” and urged its government to “immediately stop its disproportionate use of force.”

The Middle East has long been a core issue for the conference, which was founded in 1969 in response to an arson attack on the al-Aqsa mosque in Jerusalem. The group aims to promote Islamic unity and serve as a voice for the Muslim world.

Some 40 heads of state were attending the conference including President Ahmadinejad of Iran and Prime Minister al-Maliki of Iraq.

A draft declaration to be adopted by the leaders “backs Palestine, and condemns Israel for what it is doing in Gaza,” the foreign minister of the Palestinian Authority, Riad Malki, said.