Gaza - Ma'an - At least three Palestinians were killed by Israeli aircraft fire in central Gaza early Sunday evening, medics reported.

They were identified as Hasan Al-Qatarawi,22, and Awad Nasir, 29, both from from Deir Al-Balah, as well as Hudayfa Hams, 23, from Nusseirat refugee camp.

All three were transferred to Al-Aqsa Hospital in Gaza City, according to Muawiya Hassanein, the Gaza Health Ministry's director of ambulance and emergency services.

Israel's army said its air force targeted "four operatives of the Islamic Jihad terrorist organization's central region." Awad Nasir, one of the Palestinians killed, "was one of the terror organization's senior field commanders and is known to be behind dozens of IED and gunfire attacks," a statement alleged.

Earlier, a military spokesman told Ma'an the airstrike targeted "a squad of terrorists in physical preparation of launching rockets" into southern Israel. "We will not tolerate the firing of rockets by terrorists into Israel, or any attempt to disrupt the calm in Israel's southern communities, and will respond," the spokesman added.

Also on Sunday, two Palestinians were shot dead by Israeli artillery in northern Gaza, Hassanein reported. He said they were shot by tank fire near an excavation site at the former Dugnit settlement. Witnesses reported hearing artillery shelling, expecting those killed to be workers in the area.

An Israeli military spokesman said the army was not familiar with that incident.

Late Thursday night, Israeli warplanes carried out a series of raids on sites throughout the Gaza Strip, killing three Palestinians. A Palestinian was seriously injured in a Israeli artillery shelling on farmlands east of the Al-Maghazi Refugee Camp.

The incident was the latest in an escalating string of cross-border violence, with two projectiles reportedly launched from Gaza and landing in southern Israel on Saturday morning.

Friday saw four airstrikes hit locations across the besieged coastal area, reportedly in retaliation for a series of mortar shell barrages launched by the An-Nasser Salah Ad-Din Brigades, the military wing of the Popular Resistance Committees.