SIDON, Lebanon (AP) _ Israeli planes attacked Palestinian targets on the outskirts of this southern port city Wednesday, killing 10 civilians and wounding 28, police said.

It was the second-heaviest casualty toll of Israel's 14 air strikes in Lebanon this year. Fifteen people were killed and 39 wounded in the last raid in the area on Friday.

Radical guerrilla factions vowed retaliation for the 5:45 a.m. raid.

Police said four jets, protected by six other warplanes, approached the outskirts of Sidon, 25 miles south of Beirut and 37 miles north of the Israeli border. The jets dived over the area in three bombing sorties.

The densley populated Safsaf residential neighborhood in Ein el-Hilweh, Lebanon's biggest refugee camp, took the brunt of the 30-minute attack, police and local reporters said.

They said four rockets destroyed a block of 15 shacks in Safsaf, where all the casualties were.

Police said the jets also attacked two command posts of the Palestine Liberation Organization's Fatah guerrillas, but no one was hurt there.

In the Safsaf neighborhood, flames leapt from the ruined shacks. Women in nightgowns screamed and cried as rescuers pulled bodies from the smoldering rubble, local reporter Ahmed Mantash said from the scene.

''Please wait. Please have mercy. Please let me see him for the last time,'' screamed, Amneh Fadl, as rescuers carried away the body of her 14- year-old son Ahmed from the family's ruined home.

The Israeli military command in Tel Aviv said ''terrorist headquarters southeast of the port of Sidon'' were targeted in the attack. ''All our planes returned safely.''

About 60,000 people live in Ein el-Hilweh.

The Syrian-backed Popular Front for the Liberation of Palestine-General Command vowed ''a painful and severe retaliation.''

The terrorist group led by Abu Nidal, whose real name is Sabri el-Banna, vowed in a separate statement ''to teach the enemy a string of unforgettable lessons.''

Reporters who witnessed the attack said guerrillas fired ground-to-air missiles that were deflected by hot-air balloons released by the Israeli pilots.

Wednesday's raid raised the overall toll in Israeli air raids on south Lebanon this year to 42 killed and 131 wounded.

At a meeting last month in Algiers, the PLO vowed to escalate its fight against Israel. There has also been an increase in clashes between Israelis and Iranian-backed Shiite Moslem fundamentalists in south Lebanon.

Palestinian and Western sources say more than 4,000 PLO fighters have returned to Lebanon in the last 18 months.

PLO leader Yasser Arafat and his followers were forced out of Beirut, once their Middle East power base, after Israel's 1982 invasion. The Israelis pulled out most of the forces in 1985.