Thousands of Palestinians attended the funeral Saturday of a young female volunteer medic killed by Israeli fire in violence on the border in southern Gaza.
Hours later, Israel said militants in the Palestinian enclave fired projectiles at the south of the country, raising fears of a fresh escalation just days after a ceasefire brought an end to the worst flare-up since a 2014 war.
Razan al-Najjar, 21, a volunteer with the Gaza health ministry, was fatally shot in the chest near Khan Yunis on Friday.
Ambulances and medical crews attended the funeral, with her father holding the white blood-stained medics' jacket she wore when she was shot, as mourners called for revenge.
Israeli troops have shot dead over 120 Gazans since March 30 during border protests demanding the return of Palestinians to land they fled or were expelled from during the 1948 war surrounding Israel's creation.
Following the funeral, several Gazans were wounded in clashes east of Khan Yunis, health ministry spokesman Ashraf al-Qudra said.
The Israeli army said "a terror cell" had infiltrated from southern Gaza. Soldiers shot at the Palestinians, who returned to the enclave.
Hours later, the army identified "two launches" from Gaza at southern Israel, where air raid sirens sent residents to bomb shelters.
The Iron Dome aerial defence system intercepted one of the projectiles, while the other was believed to have fallen short of its target and hit within Gaza, according to the army.
A Palestinian security official then said an Israel tank fired at a Hamas observation post east of Gaza City, but there were no casualties.
The launches were the first since Israel said it struck scores of militant sites in Gaza earlier this week in retaliation for a barrage of rockets and missiles fired from the territory.
Prime Minister Benjamin Netanyahu said after the strikes that Israel's military had delivered the "harshest blow" in years to Gaza militants.
Palestinian Islamist groups in Gaza, including the strip's rulers Hamas, said a ceasefire deal was reached after the flare-up, although there was no confirmation from Israel.
The army said that the demonstrations on Friday at which Najjar was killed included "thousands of rioters" at five locations along the border, "burning tyres...and attempting to damage security infrastructure".
Shots were fired at an army vehicle and a Palestinian had crossed into Israel, planted a grenade and returned to Gaza, it said.
The army said that cases such as Najjar's "in which civilians are allegedly killed" by Israeli fire "are thoroughly examined" by an internal military committee.
The UN envoy for the Middle East, Nickolay Mladenov, said in a tweet that "Medical workers are #NotATarget!" and that "Israel needs to calibrate its use of force and Hamas need to prevent incidents at the fence."
The Palestinian Medical Relief Society said Najjar was shot "as she was attempting to provide first aid to an injured protester", with three other first responders also hit by live fire on Friday.
"Shooting at medical personnel is a war crime under the Geneva conventions," the PMRC said in a statement, demanding "an immediate international response to Israeli humanitarian law violations in Gaza".
Najjar's death brings the toll of Gazans killed by Israeli fire since the end of March to 123.
The demonstrations and clashes peaked on May 14 when at least 61 Palestinians were killed in clashes as tens of thousands of Gazans protested the US transfer of its embassy in Israel to Jerusalem the same day.
Low-level demonstrations have continued since.
Speaking at Najjar's funeral, Khaled al-Batsh, one of the protest organisers, called on Gazans to "continue the return marches and break the (Israeli) siege with peaceful tools".
*This story was edited by Ahram Online.