JERUSALEM (AP) _ Israeli troops pursuing Palestinian stone-throwers fired tear gas into a U.N. clinic in Gaza City today and 66 toddlers were treated for inhaling the fumes, the army said.

Also today, 17-year-old Israeli going to pray at the Western Wall was stabbed twice in the stomach in Jerusalem's walled Old City, authorities said. A police roundup of Palestinian suspects set off more violence.

The incidents came the day after Prime Minister Yitzhak Shamir won a vote of confidence in Parliament for his new right-wing government. Cabinet members today promised new steps to put down the 2 1/2 -year-old Palestinian uprising.

Israel radio reported that the new defense minister, Moshe Arens, began consulting high-ranking army officers today on how to end the uprising in the Israeli-occupied West Bank and Gaza Strip.

The new foreign minister, David Levy, suggested the army could withdraw from the occupied lands as part of a peace settlement. But he repeated the new government's opposition to Palestinian demands for statehood in the territories.

The new government's agriculture minister, Rafael Eitan, who led Israel's forces in the 1982 invasion of Lebanon, suggested on army radio that more Palestinians be deported.

''Instead of shooting at children you have to deport those responsible, the inciters, the organizers,'' he said. Since the start of the uprising in December 1987, 60 Arabs have been expelled to neighboring Lebanon.

An army official said soldiers fired tear gas into the United Nations' Rimal Health Center in Gaza after their patrol came under a barrage of stones and blocks. He said the rocks were thrown from the clinic compound.

Soldiers are barred from firing tear gas into enclosed spaces and the troops involved will be punished, said the official, speaking on condition of anonymity.

The army said 66 infants and toddlers were affected by the tear gas. Doctors at nearby Nasser Hospital said they treated 58 of the youngsters between the ages of one month and three years, and that 16 of those were admitted.

Rolf van Oye, a spokesman for the U.N. Relief and Works Agency, said a complaint will be filed with the Israeli government.

After today's stabbing in Jerusalem, police seized up about 100 Palestinians near Damascus Gate, one of the main entrances to the Old City, said Jersualem police commander Arieh Bibi.

The arrests set off a spate of stone-throwing at Israeli cars on Sultan Suleiman Street just outside the city walls, but no injuries were reported.

The victim, identified as Yosef Edri, was in moderate condition at Sharei Tzadek Hospital, spokeswoman Orna Cohen said. He is a student at a yeshiva, or Jewish seminary, and is from Dimona in Israel's Negev Desert.

Bibi told Israel radio that police had recovered the knife.

In the West Bank and Gaza Strip, meanwhile, soldiers destroyed three houses of Palestinians accused of throwing firebombs or killing suspected Arab collaborators and sealed two other homes of Palestinian suspects.

One of the suspects, 25-year-old Abdel Hakim Shana, was convicted of murdering alleged collaborators and sentenced to life imprisonment. Soldiers tore down the four-room house owned by his father, which was home to a family of 12.

The Supreme Court rejected appeals from some families of the suspects. U.S. policy opposes the demolition of houses as an unfair collective punishment.

The Israeli Information Center for Human Rights in the Occupied Territories said there has been a marked decline in recent months in destruction of houses by the army.

It said that through the end of May a total of 293 houses were destroyed and 173 sealed for security reasons. Several hundred others have been destroyed for being built without a permit.