Israel’s chief military spokesman said if violence drags on along the Gaza border, Israel will expand its reaction to strike the militants behind it.
Brig Gen Ronen Manelis said the military has thus far restricted its response to those trying to breach its border, but if attacks continue it will go after militants “in other places too”.
Thousands of Palestinians marched to Gaza’s border with Israel on Friday in the largest such demonstration in recent memory.
Fifteen Palestinians were killed by Israeli fire on the first day of what Hamas organisers said will be six weeks of daily protests against a border blockade.
It was the bloodiest day in Gaza since the 2014 cross-border war between Israel and Hamas.
Brig Gen Manelis said all those killed were engaged in violence.