NEW YORK — The capture of Mohammed "Abu" Abbas may advance the U.S. war on terror, but it also could set off a political time bomb.

Less than a day after U.S. Special Operations Forces in Baghdad nabbed the mastermind of the infamous 1985 Achille Lauro cruise ship hijacking, parties ranging from the Anti-Defamation League to Italian authorities to PLO officials fought to influence his fate.

On Wednesday, the ADL called on Attorney General John Ashcroft to bring Abbas to the United States to stand trial for the murder of Leon Klinghoffer, a disabled American Jewish passenger who was shot after the ship was hijacked. Klinghoffer was then dumped in his wheelchair into the Mediterranean.

The United States should be the country to bring Abbas to justice because "it's an American citizen who was murdered," argued Abraham Foxman, the ADL's national director. "We urge the Department of Justice to seize this moment to strike another blow in this nation's war on terrorism."

Meanwhile, the Palestinian Authority demanded that Abbas be freed, saying his arrest violated the Oslo peace accords and subsequent interim deals.

"We demand the United States release Abu Abbas," Palestinian Authority Cabinet minister Saeb Erekat told Reuters. "It has no right to imprison him."

According to Erekat, the Israeli-Palestinian peace pact, brokered by the United States, said PLO members should not be detained or charged for any terrorist attacks they committed before Sept. 13, 1993.

With apparent American and Israeli approval, Abbas was allowed to return to Palestinian areas several times starting in 1996, and even lived openly in the Gaza Strip for a time.

Israeli officials in the United States could not be reached for comment Wednesday, the eve of Passover.

Meanwhile, Italy — which let Abbas leave the country immediately after the attack rather than fall into U.S. hands and then, in 1986, tried him in absentia and sentenced him to life in prison — pledged to seek his extradition.

"We will have to clarify some legal questions as to whom to request the extradition, which we'll do as soon as possible," Italian Justice Minister Roberto Castelli told the Associated Press.

A U.S. State Department official, meanwhile, was quoted in the Israeli daily Ha'aretz as saying that the 1995 deal did not apply to "the legal status of persons detained in a third country."

But with U.S. Special Operations and 3rd Infantry Division forces holding Abbas in Iraq, it seems the United States will have the final word, some experts say.

"By all legal rationales at this point, with his life sentence in absentia, the Italians have first dibs," terrorism expert Steven Emerson said. "But possession is nine-tenths of the law, so of course the United States can decide what to do."

Emerson said he believes there was some tacit agreement among the United States, Israel and the Palestinian Authority to allow Abbas and other Palestinians into Palestinian-run areas after Oslo, provided they renounced terrorism.

"What they did with Abbas was no different than with Arafat: They wiped the slate clean," he said.

With Abbas having been captured during the war in Iraq, "the situation has changed," Foxman said.

"Look where he was captured," Foxman said. "Look where he was hiding out. He was captured during wartime, and it's a new status for him, and for us."

After Baghdad fell last week, Abbas traveled to the northern city of Mosul and on to the Syrian border, but Syrian authorities turned him away, the AP reported.

Someone tipped off U.S. officials to Abbas' whereabouts, and U.S. forces were led to a safe house on the Tigris River south of Baghdad.

Special Forces raided the house. Abbas had fled, but they found Lebanese and Yemeni passports, thousands of dollars, rocket-propelled grenade launchers and some documents.

Abbas later returned to the city and was captured along with several others.