JERUSALEM, JAN. 22 -- Israeli police formally invoked emergency powers tonight and placed an Arab East Jerusalem neighborhood under curfew for the first time in at least a decade following rioting in the area.

Jerusalem Police Chief Yosef Yehudai said he had requested and received the sweeping security powers from the Army in order to seal off part of the Tur neighborhood on the Mount of Olives, a holy site for Christians, Moslems and Jews. Police ordered residents to remain in their homes after demonstrators cut off the main road, threw stones and burned tires today.

The new measure was a further sign that the civil violence that has swept the occupied West Bank and Gaza Strip for more than six weeks has spread into Jerusalem. It immediately set off a political controversy among Israeli officials, with Jerusalem Mayor Teddy Kollek denouncing the curfew as a threat to the city's image as a haven of relative tolerance and peaceful coexistence between Arabs and Jews.

"We're against it," said Sivannah Meryn, a spokesman for Kollek, about the imposition of the curfew. "We were not involved in the decision to do so, and we will try to do something about it."

But Police Chief Yehudai, speaking to reporters at the scene, said that the restrictions were necessary to restore order in the area and that, if necessary, police would impose curfews on other Arab neighborhoods as well. "I hope all the others will get the message," he said.

There was some confusion about the duration and extent of the curfew. An Army spokesman said the measure was effective for 25 hours, but Yehudai said it would be imposed for at least two days. He said he had not yet decided whether to allow affected residents to go to work during the curfew, but he would allow patients to come and go from a hospital inside the restricted zone.

Under Israel's governmental system, Yehudai answers not to Kollek but to Israeli Police Minister Haim Bar-Lev, who has taken a hard line on the violence in the occupied territories in which at least 36 Palestinians have been shot dead by Israelis.

East Jerusalem was one of the areas occupied by Israeli forces after their victory in the June 1967 war. But unlike the West Bank and Gaza, which have remained under military occupation ever since, East Jerusalem was quickly annexed and placed under Israeli sovereignty and civilian law. The Golan Heights, captured from Syria in 1967, were annexed in 1981.

As a result, Jerusalem's Arab residents are considered part of Israel proper and enjoy certain civil rights denied Palestinians in the West Bank. In order to impose a curfew here, police must receive authority from the Army, specifically from Maj. Gen. Amram Mitzna, the military commander of central Israel and the West Bank.

Political sources said Israel's 10-member inner Cabinet secretly authorized Mitzna to grant police emergency powers at a meeting on Wednesday. At that same meeting, the inner Cabinet endorsed Defense Minister Yitzhak Rabin's newly stated "broken bones" policy of allowing soldiers to pursue and assault Palestinian rioters with clubs rather than use live ammunition.

The sources said the inner Cabinet specifically authorized Mitzna to allow police to single out one Arab neighborhood for curfew in order to warn the city's Palestinians that their special status as residents of Jerusalem does not give them immunity from the tough measures employed against Arab rioters elsewhere.

Bar-Lev and Rabin reportedly pushed for the measures at the session, overriding the opposition of Kollek, a highly popular political figure here and an ally of Foreign Minister Shimon Peres. All four are members of the Labor Party, the more liberal of the two main political blocs in Israel's coalition government.

The main Tur Road has been a scene of regular disturbances since the protests first broke out in the city on Dec. 19, according to Yehudai. It was cut off at least four times in the past week by demonstrators and numerous other times during the last month, he said. There have been scattered incidents of stone throwing and rioting in other parts of the city in recent weeks.

Trouble broke out again this afternoon and worsened this evening, police said. Tear gas was used to disperse several dozen rioters, and at 9 p.m. Yehudai asked for and received permission from Mitzna to invoke the emergency powers. The police chief said he was using 60 to 80 policemen to seal off an area of about 1,000 residents.

Using the new powers, authorized under 1945 emergency regulations drawn up during the British mandate over Palestine, police can round up suspects and hold them for up to 18 days without charge. Normally such suspects must be charged or released within 48 hours.

At first it appeared that the curfew had stranded 300 tourists staying at the Intercontinental Hotel on the Mount of Olives. But Yehudai said the measure did not apply to the hotel and that guests could move freely along a side road leading to the Intercontinental.

It was also unclear whether emergency measures had ever been used since the city was reunited in 1967. Longtime residents recalled that curfews had been imposed briefly on some areas following terrorist incidents in the late 1960s and early '70s, but said such measures had never been used to deal with rioting.

The action appeared to catch Jerusalem officials by surprise, because the city had appeared relatively calm today despite the fact it was the Moslem sabbath. About 600 police and paramilitary Border Police lined Jerusalem's Old City outside the Temple Mount, a holy site that was the scene of large-scale rioting and police retaliation last Friday. A few hundred worshippers prayed at two mosques on the Temple Mount this morning, and four Palestinians reportedly were arrested for attempting to hold an illegal demonstration, but otherwise the day passed without incident.

Arab merchants continued the commercial strike that they have honored for the past two weeks. There has been speculation that police might invoke emergency powers to force the shops open, but Kollek so far has been successful in blocking such an action.