JERUSALEM, JAN. 23 -- Tens of thousands of Israeli Jews and Arabs today protested the government's "iron fist" policy in suppressing civil disturbances in the occupied West Bank and Gaza Strip. The protests signaled the reemergence of organized opposition here.

The larger of two rallies took place tonight in Tel Aviv, where Jewish Israelis, marching under the banner of the antiwar Peace Now group, staged the country's largest protest since a 1982 demonstration against the Lebanon war. There was no official police estimate immediately available but witnesses said the attendance was at least 50,000.

Earlier in the day in Nazareth, political center of Israel's 750,000 Arab citizens, about 7,000 protesters waved the banned Palestinian flag while demonstrating peacefully in support of their brethren in the occupied territories. The Arab rally contrasted sharply with a similar protest march a month ago that degenerated into a stone-throwing clash with Israeli police.

The two rallies marked the first concerted attempt by liberal and left-wing critics to assert opposition to the hard-line stance taken by Israel's coalition government since the unrest began more than six weeks ago and to reverse a rightward trend in Jewish public opinion here. Polls have indicated that most Israelis initially reacted to the wave of unrest by supporting the hard-line law-and-order position epitomized by the statements of Defense Minister Yitzhak Rabin.

But the policy has created growing strains within Rabin's Labor Party, the more liberal of the two main parties in the uneasy coalition government. Underscoring those strains was the announced resignation today from Labor of Knesset member Abdul Wahab Darawshe, who told the cheering crowd in Nazareth that he was protesting Rabin's policies.

Peace Now organized the biggest political protest in this country's history in September 1982 when more than 300,000 Israelis gathered in Tel Aviv to protest the massacre of hundreds of Palestinian refugees in Beirut's Sabra and Shatila camps by Christian militiamen allied with Israel. But Peace Now has been largely dormant in recent years, and two protests by the group last month against government policies in the occupied territories fizzled.

Tonight was different, and speakers and organizers said the larger crowd reflected the growing unease with Army tactics that have resulted in Israeli soldiers shooting at least 38 Palestinians to death and wounding more than 200 others.

Speaker after speaker drew parallels between Israel's attempt to smother Palestinian nationalism in the territories and the ill-fated Lebanon invasion.

"The hard fist, the harder fist, the iron fist -- where has it gotten us?" asked Peace Now leader Tzali Rehsef. "We have come here tonight in our tens of thousands to say no. We are not here to appease our consciences. We fought against Lebanon, and they got us out of Lebanon."

The thrust of the speakers' concern was not so much toward the Palestinians in the territories as toward the Israeli soldiers who have been ordered to carry out a policy that Rabin described earlier this week as one of "force, power and beatings."

"Who do the blows hurt more -- the young Arabs hit or the young soldiers doing the hitting?" asked Danny Gal, a reserve military officer. "The blows of those hit will go away in a few days. I don't know if the blows to the heart of those who do the hitting will ever go away."

It was a mixed crowd, with many middle-aged parents scattered among the mostly young demonstrators. One of the protesters, Navah Eisen, brought along her son, who currently is serving in an Army unit in the Gaza Strip.

The son, who refused to give his name, said soldiers had no choice but to carry out their orders. He said it was better to beat Palestinian demonstrators than to shoot them, but his mother said she was deeply disturbed.

"What will happen to him when he kills his first demonstrator?" she asked. "In Lebanon I was afraid for his life. Now I am afraid for his soul."

In the Arab rally in Nazareth, Israeli police stayed largely out of sight and ignored the flag of the outlawed Palestine Liberation Organization and to marchers chanting, "No substitute for the PLO." Among the placards displayed -- in English, Hebrew and Arabic -- were black signs noting the names of Palestinians killed in the past six weeks.

Leaders of various Israeli Arab political groups blamed the stone-throwing protest in Nazareth last month on an overly visible police presence and had promised to maintain law and order today if security forces kept a low profile.

The announced resignation of Darwashe -- Labor's only Arab Knesset member and one of five Arabs in the 120-seat body -- could be a serious blow to the party. Some party leaders have expressed the fear that the hard line taken by Rabin in recent weeks could cause a hemorrhage of support on the party's left.

"Lately the hawks in the party have become stronger and stronger," said Darwashe, who urged other Israeli Arabs to leave the party as well. Labor got about 6 percent of its votes from Israeli Arabs in the 1984 parliamentary elections, and analysts said the loss of some or all of this support could make a critical difference in the next elections in November.

Despite the rhetoric and chants for an end to deportations, administrative arrest, beatings and other aspects of the government's crackdown in the occupied territories, the underlying tone of the meeting was moderate.

Sobered by attacks from leading Jewish politicians of both ruling parties who have all but accused Israeli Arabs of treason in the wake of last month's violent clash in Nazareth, community leaders vetoed suggestions for holding a general strike in favor of today's lower key demonstrations.

Analysts said Israeli Arabs wanted to demonstrate support for their fellow Arabs in the occupied territories without running the risk of a crackdown on their own community, which is torn between nationalist sympathies and steady economic, if not social, assimilation into the fabric of the predominantly Jewish state.

In walking this narrow line, Arab Israelis were following the lead of the locally well entrenched communist party, Rakah, which has both Arab and Jewish supporters.

"We know their limits as much as we know our limits," said Emile Habibi, an Israeli Arab writer, communist and former Knesset member.

Also tonight, Jerusalem police lifted the curfew that they imposed yesterday on a section of Arab East Jerusalem under emergency powers granted them by the Army. The curfew marked the first time in at least a decade that such powers were used in East Jerusalem, which was annexed by Israel in 1967 and, unlike the West Bank and Gaza, is considered part of Israeli territory.

The measure had been opposed by Jerusalem Mayor Teddy Kollek, who told reporters that he had not been consulted about the curfew and believed that it was unnecessary and damaging to the city's reputation as a haven of relative peace between Arabs and Jews.

Police imposed the curfew on part of the Tur neighborhood and ordered residents to their homes after some stone-throwing and tire-burning incidents there. They lifted the curfew after rounding up all of the male residents at a local schoolyard for interrogation and arresting four for alleged involvement in the rioting. There were scattered disturbances in two other sections of the city today.

Israel radio reported tonight that Morris Abram, chairman of the Conference of Presidents of American Jewish Organizations and in the past a vocal supporter of Israeli policy, telephoned Defense Minister Rabin to express "sharp criticism" and "shock" over the new Israeli policy of administering beatings to alleged Palestinian demonstrators in the occupied territories and over Rabin's recent public statements.

Abram said that while it was not his business to tell the defense minister what to do, American Jewish organizations would no longer be in the position to defend Israeli actions in the territories, the radio reported.