12 Guerrillas Die in Israeli Raid on Base : Mideast: The death toll in the air attack on a PLO facility is the highest of the year. In Jerusalem, an Arab woman is killed by her own bomb.

Israeli planes bombed a PLO guerrilla base near Sidon early today, killing all 12 of the fighters manning it, police and the PLO said. It was the highest death toll in 21 such attacks this year.

The police report said the jets destroyed a one-story base belonging to Yasser Arafat’s Fatah, the Palestine Liberation Organization’s largest faction.

The base was in a lemon grove 7 1/2 miles southeast of Sidon, a southern port city that is the Palestinians’ main stronghold in Lebanon.

In Jerusalem, the Israeli military command said its planes returned safely to base after hitting “a launching pad for attacks on Israel.”

The air raid came a day after Soviet-designed Katyusha rockets landed in Israel’s self-designated security zone and across the border in northern Israel. The rockets caused no damage or injuries.

Police and the PLO confirmed in separate statements that all the guerrillas were killed.

“There were no survivors. Those dug out alive died in ambulances before reaching hospital,” a police spokesman said.

Police said 28 people were killed and 82 wounded in the 20 previous Israel raids into Lebanon this year.

In Jerusalem today, a bomb ripped through a toilet at an outdoor market in the heart of the Jewish quarter, killing an Arab woman who apparently was handling the explosives, police said.

They said the victim was a 24-year-old woman from the occupied West Bank.

“Apparently the person who was handling the charge was killed in this toilet stall,” said police Commissioner Yaacov Terner. She was alone in the toilet, and there were no other casualties, he said.

The explosion occurred at about 11:30 a.m. at the Mahane Yehuda market. Terner said the woman was “torn to pieces,” but a witness said she was still alive immediately after the blast.

Shopkeeper Meir Cohen said he ran into the toilet and found the woman lying under a fallen door. “She was alive, the woman. I lifted her head. She moved her head as if she wanted to speak, wanted help,” he said.

Cohen said she had something in her hand that he feared might be another bomb, so he ran to nearby police to summon help.

A PLO military communique issued in Tunis claimed the Israeli air strike was part of a “massive military operation” Israel was planning in southern Lebanon.

It said Israel pushed troop reinforcements “estimated at two brigades” into its self-designated security zone in southern Lebanon three days ago, but gave no other details.

The reported buildup could not be independently confirmed.

Fatah, the largest and oldest of nine groups under the PLO, marks the 26th anniversary of its foundation Tuesday.

In the West Bank and Gaza Strip, the army today confined 1 million Arab’s to their homes ahead of the Fatah anniversary. Authorities closed schools in the territories.