The local commanders of Hamas' military wing were killed by tank fire, Palestinian officials said on Friday, while the Israeli army said five of its soldiers were wounded by an explosive device.
Palestinian officials said Rabieh Barikeh was killed instantly in the firefight late Thursday night and Khaled Abu Bakr died of his wounds during the night.
The bodies of Mohammed al-Qassas and Mohammed Daoud were discovered later. They said all were local commanders of Hamas's Ezzedine al-Qassam military wing.
The Israeli military said the fighting erupted when an explosive device went off as troops were clearing a tunnel from the Gaza Strip into occupied Palestinian land.
During the operation, Hamas targeted the Israeli soldiers with an explosive device, wounding five of them, it said in a statement.
In response, "the soldiers opened fire and directly hit” a Palestinian and Israeli warplanes struck an additional tunnel located in the southern Gaza Strip, it said.
No Palestinian casualties were reported in that strike.
During the exchange, Hamas TV said, three mortar shells were fired from Gaza into southern Israel.
The Israeli army reported only one, which it said fell in an open field, causing no injury or damage.
BA/BA