JERUSALEM, Oct. 27 (AP)--Palestinians poured out of mosques after midday prayers Friday and clashed with Israeli troops in violence that left four Palestinians dead, more than 150 injured and clouds of smoke and tear gas over cities across the West Bank and Gaza Strip.

Islamic militants, chanting ``We want a big bomb!'' also warned at mass rallies that they would unleash more suicide bombers on Israel.

Friday's heightened unrest, which followed several days of comparatively low levels of violence, could affect efforts by President Clinton to revive peace talks. Clinton has offered to play host to Israeli Prime Minister Ehud Barak and Palestinian leader Yasser Arafat at separate talks in Washington.

``We've got to get the level of violence down before there can be a resumption of negotiations,'' Clinton told reporters at the White House.

Israel, which has suspended peace negotiations, insists that restoring calm is a prerequisite for new talks. But Palestinian street activists, and some Palestinian leaders, have called for sustained street confrontations as the best way to put pressure on Israel.

Palestinians have declared Fridays, the Muslim holy day, a ``Day of Rage'' since fighting erupted a month ago.

Responding to the call on this particular Friday, thousands of rock-throwers--and a few gunmen--took part in confrontations across the West Bank and Gaza Strip.

At a traffic circle north of the West Bank town of Ramallah, acrid smoke from a burning car rose into the air as Israeli soldiers fired at stone-throwers from behind a line of jeeps. Palestinian gunmen at one point opened fire at Israeli soldiers, and a 27-year-old Palestinian was killed by return fire.

Three more Palestinians, including a 15-year-old boy, were killed in clashes in the towns of Tulkarem and Qalqiliya, and at the Erez crossing between Israel and Gaza. In all, 152 Palestinians were injured Friday, doctors said.

The deaths brought to 133 the number of people killed in 30 days of Israeli-Palestinian fighting, the vast majority of them Palestinians. More than 5,000 Palestinians have been injured, according to Palestinian hospital officials.

In the West Bank town of Nablus, about 2,000 supporters of the Islamic militant group Hamas marched through town chanting ``We want a big bomb.''

``The only way to respond to Israeli attacks is through military operations,'' said Salah Darwazeh, a Hamas leader in Nablus, referring to suicide bombings carried out in recent years by the Hamas military wing, Izzedine al Qassam.

In the Gaza refugee camp of Jebaliya, more than 10,000 Hamas supporters attended a rally led by several dozen masked men wearing identical white robes with the logo, ``The martyrs of Al Qassam.''

One of the masked men wore a belt holding what was meant to resemble bombs and sticks of explosives.

Israel has been on high alert for new suicide attacks since several dozen Islamic militants were released from Palestinian jails two weeks ago. On Thursday, a 24-year-old kindergarten janitor rode his bicycle to an Israeli army post in Gaza and detonated explosives strapped to his back, killing himself and injuring a soldier.

In response, Israeli forces destroyed a house overlooking the base and uprooted trees that gave cover to Palestinian attackers.

Israeli security officials warned of an escalation of the conflict. ``The operators are out there, at large,'' said army spokesman Col. Raanan Gissin.

In Jerusalem, Israel barred Palestinian men under 35 from praying at the Al Aqsa Mosque compound on Jerusalem's Haram as-Sharif, the Noble Sanctuary, a hill known to Jews as the Temple Mount and holy to both religions. Police said they imposed the restrictions to prevent possible clashes after prayers.

Worshippers dispersed quietly after planting a Palestinian flag on one of the two mosques in the compound. A visit to the site by Israel's hawkish opposition leader Ariel Sharon preceded the Israeli-Palestinian fighting Sept. 28. The Temple Mount is the site of the biblical Jewish Temple, the holiest shrine of Judaism.

In the Jewish West Bank settlement of Efrat, the main synagogue was vandalized overnight, and settlers said they suspected Palestinian intruders. The synagogue was flooded--the vandals had turned on water hoses--and swastikas were spray-painted on the walls along with slogans in Arabic and Hebrew.

Efrat Mayor Eitan Golan said security at the settlement, located between Jerusalem and Hebron, must be improved. ``Today they spray paint. Tomorrow they could spray gunfire,'' he said.

Clinton, meanwhile, called Israeli Prime Minister Ehud Barak late Thursday to discuss the situation, the White House said. Clinton has invited Barak and Arafat to separate talks in Washington.

Barak and Sharon worked on forging a broad coalition that could salvage Barak's minority government. Barak needs such a coalition to stay in power, while Sharon is seeking a prime political role and a say in security affairs.

Sharon raised harsh conditions, saying his party will never accept surrendering control over any area of Jerusalem, including the Temple Mount, or giving the West Bank's strategic Jordan Valley to the Palestinians. Barak turned down Sharon's conditions.