Stepping up its crackdown in the occupied West Bank, the Israeli Army today ordered three Palestinians deported for "subversive political activity" and jailed 29 others without charge under administrative detention orders.

Meanwhile, Israeli security authorities tonight were holding in a prison near Haifa an American and an Australian, accusing them of transporting a Palestinian terrorist squad toward Lebanon, from which authorities said the squad planned to launch an attack on Israel.

Neither Israeli officials nor the U.S. Embassy in Tel Aviv would identify the American, but Foreign Ministry and security sources said he was a charter-yacht operator who had been paid a "large sum of money" by a guerrilla unit of the Fatah wing of the Palestine Liberation Organization to transport the unit from Athens to Sidon in southern Lebanon.

The Army said the yacht Kasilradi was intercepted early Sunday en route to Sidon. An Army spokesman said the Palestinian passengers told of plans for a "showpiece attack" against a civilian target in the Galilee, in northern Israel.

The Army command said Fatah had trained the Palestinians in Algeria and passed them through Tunis before they boarded the yacht in Athens. Israeli authorities would not say where the yacht was intercepted but said that two weeks ago the group had been turned back by Lebanese militia while attempting to land in Sidon.

Military sources said the American and Australian were being held in a civilian prison in Kishon, separately from the Palestinians, and that no charges had yet been brought against them. A U.S. Embassy spokesman said only that a consular official visited the American today and that his name was being withheld because of "the privacy of the client relationship."

Military authorities described the West Bank deportations as "part of the ongoing security activity" in the occupied territories. It was the largest group of expulsions since the mayor and leading Islamic religious leader of Hebron and the mayor of the nearby village of Halhoul were deported in May 1980 following the massacre of six Jewish settlers in Hebron.

The Israeli Cabinet ordered a resumption of deportations this month following a wave of murders of Israelis in the West Bank or inside Israel just across the demarcation line. At least 12 Israelis have died in similar attacks which have been attributed to Palestinians.

Shmuel Goren, the government coordinator in the occupied territories, said tonight that although efforts were being made to avoid collective punishment in response to increased nationalism in the West Bank, the deportation policy would continue.

"Those against whom it is difficult to act through the courts we will make efforts to deport," Goren said on state radio. He was referring to a number of recent setbacks against deportation resulting from appeals by Palestinian defendants to the Israeli Supreme Court.

The U.S. State Department has consistantly criticized the deportation policy, saying it violates Geneva Convention provisions prohibiting the expulsion of inhabitants of an occupied territory.

The three Palestinians ordered deported today were Amin Darwish Makbul, described as a Fatah leader in the West Bank city of Nablus; Walid Mahmoud Nazal, allegedly a "senior activist" in the Democratic Front for the Liberation of Palestine, and Bahajat Mustafa Hassan, described as having participated in the stoning of Israeli soldiers and inciting to violence in meetings of Fatah.

All three, the Army command said, had served long prison terms for engaging in subversive activity but had continued the activity upon their release.

Military sources said the Palestinians jailed under administrative detention had either participated in attacks or incited others to attack Israelis in the occupied territories.