JERUSALEM, JUNE 23 -- An Israeli naval patrol sank a Palestinian boat off the southern Lebanese coast today, killing at least two gunmen who the army said planned to raid the Jewish state.

"A {gunboat} on regular patrol off the Lebanese coast destroyed a terrorist boat heading at a speed of 30 knots with terrorists planning to strike at northern Israel," an army spokeswoman said.

The incident came three days after the United States said it was ending a dialogue with the Palestine Liberation Organization over the PLO's failure to condemn an attempted seaborne attack on an Israeli beach by a PLO faction last month.

Military sources said at least two men on the speeding boat opened fire on the Israeli vessel with automatic weapons and rocket-propelled grenades.

The Israelis returned fire, destroying the craft about six miles from the Israeli border. There were no Israeli casualties, the sources said.

Hours earlier, a bomb exploded at a popular Dead Sea resort, injuring two visiting West German actors and two Israelis, one of whom was an Arab.

Police said the blast at Ein Gedi was caused by a pipe bomb similar to one that killed an Israeli and wounded nine people in a market here last month.

West German actor George Martin Bode; Ofer Ben Baruch, 21, a Jew from Jerusalem, and Salim Hadad, 28, an Israeli Arab from Peqin village, were reported in a Jerusalem hospital with light to moderate injuries.

A second, unnamed West German actor received first aid at the scene of the explosion, colleagues said.

Police assumed the bomb was planted by Palestinians waging a 30-month-old revolt against Israeli occupation of the West Bank and Gaza Strip, and questioned 37 Arab suspects seized in the vicinity by Israeli bathers.