The European Union released a statement Saturday in response to deadly clashes at the Gaza-Israel border Friday, saying they raise “serious questions about the proportionate use of force.”

Nine Palestinians were killed by Israeli army gunfire after clashes resumed between Palestinian protesters and Israeli forces along the Gaza border on Friday, Gaza’s Health Ministry reported. The dead include photojournalist Yaser Murtaja, who was shot in the chest while wearing a vest marked “press.”

“Yesterday, at least nine Palestinians, including a minor and a journalist wearing a ‘press’ jacket, were killed in Gaza and hundreds were injured by Israeli live fire,” reads the EU statement. “This raises serious questions about the proportionate use of force which must be addressed.”

It was the second consecutive Friday of mass protests known as the “March of Return,” a series of demonstrations along the border leading up to Nakba Day.

The EU statement continued: “Reports by the Israeli Defense Forces about throwing stones and firebombs against their positions and attempts to cross the fence into Israel must also be clarified.” It also called for restraint, access to medical supplies for the injured and for the Palestinian Authority to assume full responsibility in Gaza.

European Union foreign policy chief Federica Mogherini called on Saturday for an independent and transparent investigation into the Israeli military’s use of live fire during mass rallies last week, in which 15 were killed.