Palestinians are streaming to tent camps along Gaza's border with Israel for the third of what are to be weekly mass protests until mid-May.
The marches are organised by Gaza's Islamic militant Hamas, but turnout is also being driven by desperation among the territory's 2 million residents.
Marchers protest against a decade-old blockade and assert what they say is a "right of return" of Palestinian refugees to what is now Israel.
In two weeks, 34 Palestinians were killed by Israeli fire, including 27 during protests. Israel alleges Hamas is using protests as a cover for attacks. Rights groups say military's open-fire orders are unlawful.
On Friday, hundreds flocked to one of five camps near Gaza City, stepping on a large Israeli flag laid out on the ground at the entrance.
- FOLLOW News24 on Twitter