Pro-Syrian Palestinians killed 14 Palestinians who were complaining about not being paid for staging the "Palestinian demonstration" on the 5th. The Syrian government used a pro-Syrian Palestinian group to recruit Palestinians, with offers of $1,000 each if they joined the march into Israel, and $10,000 each if they were killed, and free medical care if they were injured. This was to be a non-violent demonstration to commemorate the 1967 war, which is seen as a great catastrophe by Arabs. Once in Israeli territory, Israeli troops opened fire on the demonstrators, aiming for the legs. Syria claimed that 23 people were killed and 350 injured. Israel claimed that there were few deaths, and less than a hundred injured. The money was never was paid to the demonstrators, who later went and demanded justice (and cash) from the pro-Syrian Palestinians (who then opened fire when they felt threatened.)
Odds are, Syrians killed far more Palestinians over this protest march, especially since the Syrians herded the protesters into uncleared Syrian minefields and most likely exaggerated the deaths to make Israel look bad.
