Israeli soliders who killed five Palestinian guerrillas in southern Lebanon on Christmas Day piled the bodies on top of one another and then blew them apart with explosives, a United Nations spokesman said today.

Israel denied the account of the incident as related by the spokesman fot the U.N. peacekeeping force in Lebanon. The U.N. official said the incident was witnessed by a Dutch U.N. patrol.

An Israeli military spokesman said today that Israeli troops had thrown grenades at the guerrilas during a firefight but denied that the Israelis had burned or blown up the guerrillas' bodies. He said the bodies were taken out of Lebanon and buried in Israel.

The U.N. information bureau in Beirut said in a statement released here today that five "armed elements" -- the U.N. term for Palestinian guerrillas -- had been killed in a clash with about 30 Israeli soliders on the morning of Dec. 25.

The fighting took place near the Lebanese village of Shama, about five miles north of the Israeli border, in an area nominally under U.N. control but where Israeli forces routinely roam.

The U.N. statement said: "A Dutch patrol that happened to be on the scene reported that the IDF (Israeli Defense Force) soldiers proceeded to search the bodies and then pile them up one on top of the other.

"After sprinkling them with an unidentified liquid, an explosive charge was put on top of the human pile. The device detonated as planned. A second charge went off 10 minutes later, after which the IDF patrol left the scene."

The spokesman said the U.N. command asked the International Red Cross to investigate the incident and arrange for removal of the bodies. He said the Red Cross took no action, so the U.N. command sent a team to the area four days later to bury what remained of the Palestinians.

But it was prevented from carrying out this task by Israeli soldiers who fired warning shots before carrying off the human remains in plastic bags, he said.

Washington Post correspondent William Claiborne reported from Jerusalem that an Israeli Army command gave this account today:

The five terrorists were spotted approaching a border fence just north of Israel's Kibbutz Hanita. The Israeli patrol gave chase and trapped the guerrilas in a cave. A firefight followed, and Israeli soldiers threw grenades into the cave.

"Maybe one grenade made other explosions [inside]," the spokesman said. The guerrillas had been armed with rocket-propelled grenade launchers, grenades and explosives, he said.

He said that "several days later" an Israeli force returned and removed the bodies because "nobody there wanted to bring them out." He said they were turned over to Israeli police who buried them in a "special place in Israel where these people are buried, as always in cases like this when nobody comes to take the bodies." But he said he did not know the location and probably could not reveal it in any case.

The Army command spokesman vehemently denied the charge that bodies were burned.

"The Israeli Army has never done such a thing to a body that fell in battle. It is our tradition to respect the bodies of fallen enemy," he said.

Asked about the charge that Israeli soldiers fired on a Dutch U.N. patrol, he said: "If there was fire against [U.N. troops], why is it that nobody until this moment -- days after -- has said anything? Why is it they never picked up a telephone and complained to us, the U.N. headquarters or anybody else?"