ROME, FEB. 15 -- A Cypriot ferry chartered by the Palestine Liberation Organization to carry Palestinian deportees on a protest voyage to Israel was damaged by an explosion this morning in the Cypriot port of Limassol.

Reports from Cyprus said the underwater blast blew a 21-inch hole in the hull of the 6,000-ton passenger ferry Sol Phryne. The source of the explosion remained in question.

Cypriot police were quoted as saying the blast was caused by a limpet mine attached to the ship. No injuries were reported.

PLO officials blamed the explosion on Israel, which has expressed outrage at the attempt to emulate the 1947 voyage of the ship Exodus and said it would not permit the vessel to enter Israeli territorial waters.

Israeli spokesmen declined comment on the blast, but Israeli Defense Minister Yitzhak Rabin told an Israel radio interviewer today: "The state of Israel decided it was compelled not to let them {the Palestinians} achieve their purpose, and we will do that in whatever ways it seems suitable."

The blast occurred one day after three PLO officers were killed outside of Limassol when a bomb went off in their car.

PLO spokesman Bassam Abu Sherif, speaking by telephone from Athens, said there did not appear to be any connection between the killings and the ship incident. But officials in Cyprus have indicated that the three dead PLO officials -- Mohammed Sultan, Mohammed Buheis and Marwan Kayyali -- had been in Limassol for negotiations on chartering the Sol Phryne.

The ship was to have carried from Limassol to the Israeli port of Haifa 131 Palestinians, who were deported from the Israeli-occupied West Bank and Gaza Strip, as well as a large contingent of journalists and international observers.

In what was widely viewed as a propaganda ploy, the ship was to have been dubbed "Awda," or Return, and was meant to be an allusion to the Exodus voyage in which 4,530 European Jews attempted to penetrate a British naval blockade and reach the Jewish homeland in Palestine.

Last week, when the PLO was seeking a ship to charter in Greece for the voyage, Israeli Prime Minister Yitzhak Shamir denounced the plan and said he considered it tantamount to a "declaration of war."

In Nicosia, Cyprus, The Associated Press, quoting an anonymous caller, said the U.S.-based Jewish Defense League claimed responsibility for today's blast. "This is only a warning. Next time we will bomb it {the ship} with all the people on it," the caller said. The league was founded in the 1960s by Rabbi Meir Kahane, who serves in the Israeli parliament and heads the anti-Arab Kach Party.

{In New York, the Jewish Defense League said it "applauds the bombing of the PLO pirate ship," but it claimed "no credit" for the explosion, United Press International reported.}

Western diplomats expressed doubts about the league's capability to carry out such well-planned and organized operations.

Abu Sharif, a close aide to PLO leader Yasser Arafat, accused agents of Israel's secret service, the Mossad, of setting off the ship explosion after a series of earlier attempts to sabotage the voyage.

He alleged that Mossad agents threatened Greek ship owners and captains who were negotiating with the PLO in Athens earlier this month.

The 131 Palestinian deportees have been waiting for more than a week in Greece, their originally planned departure point, awaiting completion of those negotiations. Plans for the voyage from Athens apparently were aborted in favor of a departure from Limassol aboard the Sol Phryne.

Many of the would-be passengers reportedly were at Athens International Airport today, ready to fly to Cyprus, when word first reached them that the ship had been holed at 5:30 a.m. Cyprus time.

According to diplomatic sources in Athens, private pressures were exerted against Greek merchant shipping officials to counter each PLO effort to charter a ship. PLO sources indicated that the organization had tentatively arranged for five different ships to sail from the Greek port of Piraeus in the course of last week, but each was canceled at the last moment.

Abu Sherif said the PLO was waiting for word on how soon the Sol Phryne might be repaired, but reports from Cyprus suggested repairs could take months to complete. Abu Sharif said the PLO would nevertheless continue with its plans.