JERUSALEM, DEC. 29 -- Top Israeli officials today politely but firmly rejected U.S. arguments that they should not deport Palestinians accused of instigating disturbances in the occupied territories, saying that Israelis know best how to protect their own national security.

While the comments by Prime Minister Yitzhak Shamir and Defense Minister Yitzhak Rabin stopped short of promising new expulsions, they were seen as the strongest indication yet that a move to expel at least some Palestinians is likely within days.

The remarks coincided with the arrest of at least nine Arab activists from the West Bank and Gaza Strip who are considered by informed sources as prime candidates for deportation. {News agencies quoted Israel Radio as reporting that about 20 Palestinians have been arrested in recent days on suspicion of having incited riots during the Dec. 9-21 uprising.}

"I can't say anything about how many will be deported," Shamir said during a visit to the Arab village of Abu Ghosh, just west of Jerusalem, "but we must take these measures."

Shamir rejected U.S. protests that deportations violate the Fourth Geneva Convention of 1949, saying: "The state of Israel knows how to defend its peace and security. We thank {the United States} for the advice, but we will behave according to our own understanding."

The Fourth Geneva Convention prohibits the expulsion "for any reason whatsoever" of civilians from an area under military occupation. Israel insists that the prohibition was designed to prevent deportation for forced labor, torture or extermination, while it expels people only to ensure public order and security.

Rabin, told reporters that expulsions are allowed under Israeli laws and are needed to ensure that "there will be no resumption of outbursts of public violent disorder in the future." Israel bases its legal right to expel those it deems a threat to security and order on a regulation that dates back to before its formation as a nation in 1948, in the post-World War I period when Palestine was governed by Britain under a League of Nations mandate.

The comments by Shamir and Rabin followed strong representations by U.S. officials in Tel Aviv and Washington on Monday meant to deter any Israeli expulsions.

Meanwhile, Palestinian lawyers in the West Bank announced today that they would join their counterparts in the Gaza Strip in boycotting the military trials of hundreds of Palestinians arrested in the uprising. The lawyers charge that their clients' rights are being trampled in the military's rush to convict them, charges that Israeli officials deny.