Nobody was crossing over into Israel. This incident took place at the Purple or Alpha line a ceasefire line established in 1967. You could say they were crossing over from Sria into Israeli occupied Syria, but you must know The Golan is not Israel, and is outside of Israel's internationally recognised borders.
Monitor: Airstrikes hit Islamic State stronghold in Syria, killing at least 13 (Reuters)
from the article: IDF fears continued Palestinian infiltration on Syria border