JERUSALEM, OCT. 22 -- A wave of stabbings of Israeli Jews by Palestinians in the past few days has provided new evidence of a trend, which first appeared this summer, of Palestinians shifting their weapons from stones and boycotts to knives and bombs in the long-running Arab uprising.

In the latest incidents, a Palestinian with a knife today attacked an Israeli supermarket employee in Jerusalem, lightly wounding him. In the Gaza Strip, an army soldier was slightly injured when he was assaulted by an Arab wielding an axe. Meanwhile, a 14-year-old Arab was reported killed in clashes between the army and stone-throwers in Jenin, on the West Bank.

On Sunday, three Israelis were killed in Jerusalem and a soldier in Gaza was wounded in knifings by Palestinians. Last week, two soldiers were wounded in a knife attack in the West Bank.

The intifada, as the rebellion against Israeli control of the territories it captured in 1967 is known in Arabic, began in December 1987 with confrontations between unarmed crowds and soldiers in the towns and refugee camps of the occupied West Bank and Gaza Strip. Yet recent events have sketched an entirely different profile of the conflict: a guerrilla war of stabbings and hit-and-run attacks, centered in Jerusalem rather than the territories, involving Israeli civilians as well as soldiers.

This new, more bitter brand of Israeli-Palestinian conflict has been seeping into the country ever since the breakdown last March of U.S. attempts to broker a peace process, Palestinian and Israeli observers say. Its advent was strengthened by eruption of the Persian Gulf crisis, which has caused many Palestinians to embrace the radical stance toward Israel of Iraq's Saddam Hussein.

Now, as Palestinians mourn the death of at least 19 demonstrators shot by Israeli police in a riot on Jerusalem's Temple Mount Oct. 8, a kind of watershed seems to have been reached: Few street demonstrations have occurred in Jerusalem and the territories in the last two weeks, but a wave of isolated, violent attacks have been mounted by Palestinians on Israeli soldiers and civilians.

About 50 Israelis and more than 1,000 Palestinians have been killed in the nearly three-year-old intifada. For the first time now, however, local Palestinian groups that long refrained from armed struggle have endorsed the assaults, and Palestinian political leaders have declined to condemn them.

"We are seeing an escalation in the street and among the activists that is more and more difficult to control," conceded one moderate Palestinian leader in Jerusalem, who asked not to be named. "The activists have had enough of nonviolent tactics that produced no results in advancing the Palestinian cause."

The stabbings of the last two days were carried out by lone assailants, and police said the suspect in the deaths of the three Jerusalem residents Sunday claimed he was acting independently. Still, callers to Western journalists persistently claimed responsibility for the attacks on behalf of militant Palestinian organizations such as Force 17 of the Palestine Liberation Organization.

In leaflets last week, the two largest organizations of the uprising, the PLO's Fatah and the Islamic Resistance Movement, or Hamas, endorsed armed attacks on Israeli soldiers and civilians for the first time. Although the PLO leadership in Tunis has not announced any change in policy, the Fatah leaflet issued here said stones and molotov cocktails had not achieved the Palestinians' goals, "and there is an urgent need to adopt the use of live weapons and knives," according to translations published in the Israeli press.

Hamas, a fundamentalist movement that has emerged as a rival to the PLO, told its followers to "murder and kill any soldier or Jew," adding: "They must be viewed as targets and it is compulsory to kill them and to damage their property."

The growth of Palestinian militancy has been accompanied by a radicalization of Israeli behavior. In Jerusalem, attacks by Palestinians have prompted anti-Arab rioting by Jewish crowds twice since August, including one incident in which an Arab driving his car out of the city was stoned to death. Today, police deployed some 2,000 officers in Jerusalem and closed the city to Palestinians from the West Bank to head off further violence.

Israeli commentators are warning that the radicalization of both sides threatens an explosion of intercommunal violence, particularly in Jerusalem. "Jerusalem is the focal point as the intifada again comes to life," commentator Emanuel Rosen wrote in the newspaper Maariv today. "The myth of a united Jerusalem has long been shattered; now we must prevent a mutual blood bath."

With its interwoven neighborhoods of 350,000 Jews and 150,000 Arabs, Jerusalem was an eye of relative calm in the storm of the intifada through most of its first 2 1/2 years. Captured and annexed by Israel in 1967, East Jerusalem and its Old City were patrolled by police rather than army troops, and the harsh measures of repression used against Palestinians in the West Bank and Gaza could not be applied there. Only six Jerusalem deaths had been attributed to the intifada by last June.

As mass resistance in the territories has waned, however, Jerusalem has offered a focus for the escalation of tactics. Its large Jewish population presents a ready target while its prominence has ensured that incidents there will attract widespread attention.

The escalation of events in the city can be traced to last May, when Palestinians reacted to an earlier tragedy: the murder by an Israeli gunman of seven Palestinian workers near Tel Aviv. Eight days after the incident, a bomb exploded in the central Jerusalem vegetable market, killing one person and injuring nine. In subsequent weeks, several other bombs exploded in the city.

In June, a major wave of violence erupted in Jerusalem after an Arab stabbed a boy in a Jewish neighborhood then disappeared into an adjacent Arab area. Battles erupted between Jewish and Arab residents of the two neighborhoods, and unrest rippled through the city for two weeks. Two Palestinians were killed by police in rioting.

Since Iraq invaded Kuwait Aug. 2, there has been almost continual violence in Jerusalem. Just days after the invasion, two Jewish teenagers were found dead near an Arab neighborhood, prompting Jewish riots in West Jerusalem.

Then, Palestinian sources say, activists in the city began a systematic effort to step up the uprising, drawing on the militant mood of the many Palestinians who support Saddam. By late September, the attacks had begun to grow.

On Sept. 30, for example, 100 masked Palestinians attacked a police post near the Old City with stones and iron bars. Six days later, two policemen were injured when a grenade was thrown at them in the Old City. Two days after that, on Oct. 6, a major clash broke out between police and 200 demonstrators in the neighborhood of Isawiya.

Then came the riot Oct. 8, in which up to 5,000 Palestinian demonstrators furiously clashed with police on the Temple Mount and threw stones at Jewish worshipers at the nearby Western Wall. The bloodshed that day, Palestinians now say, ensured that militants seeking to escalate the level of violence would have their way.

"It's very hard to offer another answer to your people when 20 persons have been gunned down outside the Holy Places," said a Palestinian moderate, referring to mosques on Haram Sharif, as the Temple Mount is known to Arabs. "In fact, there is no other answer, not unless we have a change in the political situation and the prospects for a real peace process."