"The fourth person, a 26-year-old, is in serious condition. He has a fractured skull and is unconscious in the ICU [intensive care unit]," Sahbani said, quoted by Al Jazeera broadcaster, specifying that three other victims underwent treatment and were sent home.
The broadcaster also noted that the Israeli airstrikes, conducted Tuesday, were aimed against Hamas militants in three locations.
Tensions between Israel and Palestine have continued to escalate through the years. Palestinians seek to create an independent state in the West Bank. The Gaza Strip, along with the Golan Heights, the West Bank and the Sinai Peninsula were seized by Israel as a result of the Arab-Israeli Six-Day War in 1967.
The Israeli side usually blames the Palestinian Hamas movement, which rules the Gaza Strip, for the attacks carried out from the territory of the Gaza Strip.