JERUSALEM, DEC. 15 -- Israeli security forces today ordered four Palestinians deported from the Gaza Strip, and cabinet ministers called for tougher measures against terrorism following Friday's killing of three Israelis at a factory near Tel Aviv.

The army closed the entire Gaza Strip and carried out intensive searches for two Palestinian brothers who are suspected in Friday's stabbings. The suspects are members of the outlawed Islamic fundamentalist movement Hamas.

An army spokesman said more than 500 Palestinians have been arrested since Friday, while Palestinian lawyers said the number was close to 1,000. By either count, it was the largest round-up since the Palestinian uprising, known as the intifada, began three years ago. Authorities said all those arrested were members of Hamas.

Palestinians claimed the arrests were made in retaliation for the killings, not in order to apprehend the suspects.

Friday night, 20 Jews were arrested for attempting revenge attacks on Arabs, and three Arab cars were set aflame in Jaffa, where the killings occurred.

Authorities said the four Gazans who were given deportation orders are Hamas activists who organized violent activity against Israelis. They were not identified.

The orders were the first issued in 16 months and seem likely to spark international protests. Palestinians say deportations are illegal under international law, but the government has maintained that they are legal under emergency defense regulations.

The United States has strongly protested past deportations, and today's orders were expected to further strain relations between the two countries, which have already been tested by the U.S. alliance with Arab nations in opposition to Iraq. Nevertheless, Israeli security officials said there could be more deportations in the next few days.

Prime Minister Yitzhak Shamir's cabinet is scheduled Sunday to discuss the slayings, and some ministers already have called for harsh punishment of Palestinians who attack Israelis.

Police Minister Roni Milo said he favors the death penalty for crimes such as the fatal knifing of three Israelis .

"My opinion in the past of the death penalty was negative," Milo told Israeli army radio. "But today I have new thoughts on the issue, and if a proposal like that was put forward I think I would support it."

The death penalty currently may be imposed only on Nazi war criminals. The only person ever executed in Israel was Adolf Eichmann, who was hanged in 1962 for running Adolf Hitler's network of death camps. A second convicted Nazi war criminal, John Demjanjuk, is appealing a 1988 death sentence.

Agriculture Minister Rafael Eitan and Science and Energy Minister Yuval Neeman called for banning all Palestinians from working in Israel and deporting leaders of the uprising.

Tel Aviv Mayor Shlomo Lahat, a member of Shamir's right-wing Likud Party, alsourged that Arabs from the territories be barred from working in Israel. But he voiced support for creation of a Palestinian state.

"All I care about is the state of Israel," Lahat told Israel TV. "The situation is getting worse every day. I think we should sit with the Palestinians and find a solution: a Palestinian state in the West Bank."

Many Israeli employers are expected to fire their Arab workers in the wake of Friday's killings. As bloodshed between Arabs and Jews has intensified in recent months, thousands of Palestinians have been fired and replaced with Soviet Jewish immigrants.

The upsurge in violence began when Israeli police shot and killed 17 Palestinians on Jerusalem's Temple Mount and Palestinians responded with stabbing attacks on Jews that have killed eight and injured dozens.

Palestinian leaders say that radicalism is increasing in their ranks and that more repressive measures will only make things worse. "The conflict could transform itself from a political conflict over borders, which is what it still is now, to a racial and religious conflict. And that's not a conflict that one can find a solution for," Palestinian activist Sari Nusseibeh said.