GAZA, DEC. 15 -- "Young people, go at them!" urged the amplified voice from the tower of the mosque across the street from this city's main hospital.

"Don't be afraid!" the voice shouted in Arabic as scores of Palestinian youths hurled rocks and molotov cocktails at armed Israeli troops on the streets below. "Don't back down!"

Mahmoud Sakhli, 22, and Ibrahim Daqar, 23, followed that advice to their deaths today, becoming two of at least four fatalities here during the bloodiest day yet in a week-long violence that a ranking United Nations official said has become "a popular uprising" in the Israeli-occupied Gaza Strip.

The two were among the casualties when Israeli forces fired on demonstrators who had taken shelter in the courtyard of Shifa Hospital. The military command confirmed that a fifth Gazan died in an Israeli hospital today of wounds incurred in an earlier clash, bringing the death toll in the Israeli-occupied territories since the trouble began last Wednesday to at least 13, nine of them in Gaza.

U.N. and hospital sources said that about 200 Palestinians had been wounded by Israeli army gunfire during the last week, including at least 11 today.

Western journalists raced up and down the 28-mile length of this overcrowded strip of Mediterranean seacoast trying to keep up with each new, violent flare-up. They found an almost desperate sense of rage among its 650,000 Palestinian occupants. They have lived under occupation since the Israelis conquered the Gaza Strip and the West Bank of the Jordan River in the 1967 Six-Day War.

"Come and kill us or get out!" angry youths shouted at the equally youthful Israeli troops who faced them in the streets outside Gaza's Shifa Hospital.

On the wall surrounding the Bureij refugee camp a few miles south of Gaza somebody had scrawled in red paint: "We will die standing, but we will not kneel."

The Gazans are increasingly angry not just at Israel, but at those whom they see as Israel's allies against the Palestinian cause.

"Look! Look!" 16-year-old Ayman Ali shouted as he thrust a spent tear-gas canister at an American reporter in Nuseirat Camp after helmeted army troops dispersed demonstrators there. "Made in USA," he read.

A Palestinian at Shifa Hospital warned three American reporters who went inside just before the fatal Israeli Army attack against demonstrators that they were entering at their own risk.

"The people are very extremist," the man said in broken English. "All of us think that you, the Americans and the Europeans, have created this problem." At least three foreign journalists were assaulted.

Mills charged that the Army had exacerbated the situation with its harsh tactics. He said U.N. officers had witnessed Palestinian youths being tied to the hoods of Israeli Army jeeps and "used as a shield" as the Israelis advanced against stone-throwers in the camps.

The United Nations, which an Israeli security source said is generally accurate, reported four dead -- the two at Shifa Hospita plus 17-year-old Talal Hwihi, shot in the neck at Beit Hanoun in the northern tip of the Gaza Strip, and Nafez Iqtifar, age unknown, killed at Deir Balah.