Nine Palestinians have been killed and hundreds of others injured in clashes with Israeli forces.
Palestinian protesters burned tyres as they demonstrated along the border with Israel, with some protesters throwing stones.
Israeli security forces fired tear gas and live rounds in response.
Health officials in Gaza said journalist Yasser Murtaga and a 16-year-old boy were among those killed.
Mr Murtaga had been covering the demonstrations for local TV company Ain Media, and is reported to have been shot in the southern town of Khuzaa.
Health officials also reported at least 48 children have been injured.
Palestinian protesters run for cover from tear gas fired by Israeli troops during a protest at the Gaza Strip's border with Israel. Picture by: Khalil Hamra/AP/Press Association Images
Israeli Defence Forces, meanwhile, said Palestinians had been rioting, claiming: "Hamas is burning tires to make a smokescreen and using it in an attempt to turn the Gaza-Israel border into a warzone, endangering civilians in Gaza and Israel alike. Hamas is literally trying to set the Gaza-Israel border on fire."
Over the past hour, rioters have attempted to damage & cross the security fence under the cover of smoke from their burning tires. They also attempted to carry out terror attacks & hurl of explosive devices & firebombs pic.twitter.com/g8fk9N4vcT
— IDF (@IDFSpokesperson) April 6, 2018
Yesterday marked the second major day of protests as part of a six-week campaign of demonstrations, with protesters calling for refugees to be allowed return to their ancestral homes in what is now Israel.
Organisers of the 'March of Return' - including Hamas - have called for peaceful protests, with tens of thousands taking part in the demonstrations.
The protests began on March 30th to mark Land Day - a day of commemoration to mark the deaths in Israel of six unarmed Arab protesters in 1976.
Demonstrations are set to end on May 15th, when Palestinians commemorate the anniversary of the creation of Israel (known by Palestinians as the 'Nakba' or 'catastrophe').
17 Palestinians are reported to have been killed during last week's border demonstrations.
On Thursday, UN Secretary General António Guterres urged all parties involved to "avoid confrontation and exercise maximum restraint".
He added: "I particularly urge Israel to exercise extreme caution with the use of force in order to avoid casualties. Civilians must be able to exercise their right to demonstrate peacefully."