(CNN) -- Three people, including a teenager, were killed Sunday and two others were injured when an Israeli tank shell landed east of the Beit Hanoun neighborhood in northern Gaza, according to Palestinian medical and security officials.
The number of dead was initially two, but a 13-year-old boy died from injuries sustained in the incident, the officials said. The other fatalities were a 61-year-old man, the teenager's grandfather, and another youth, 21.
The Israel Defense Forces said its soldiers were returning fire toward "a number of suspects" who were attempting to fire a rocket-propelled grenade in their direction. The suspects "were apparently hit," the IDF said in a statement.
Suspects were seen approaching a security fence earlier Sunday in the same area, the IDF said, and soldiers fired warning shots at them. "Two projectiles apparently landed in the same area," the statement said.
CNN's Talal Abu-Rahma and Guy Azriel contributed to this report.