The Israeli army said a firefight erupted along the border with the Gaza Strip after its troops came under attack from Palestinian sniper fire.
A Hamas militant was killed and an Israeli soldier was seriously wounded, Gaza hospital officials and the military said.
Israeli officials said it responded to the sniper attack with both tank and airstrikes after Hamas’ armed unit fired on soldiers on the Israeli side of the border.
Hamas and Palestinian medical sources said the incident took place east of the southern city of Khan Yunis and identified the dead man as Tayseer Asmairi.
The Israeli soldier, with the Bedouin Reconnaissance Battalion, suffered a chest wound and was listed in serious condition at a hospital, army officials said.
There have been sporadic clashes since Israel and Hamas ended a 50-day war with a truce on August 26. Last week, Israeli planes bombed a Hamas militant base in the Gaza Strip in response to a rocket that militants launched earlier that day.
“This attack, the second of this week, is a lethal violation of the relative quiet along the Gaza border and is a blatant breach of Israel's sovereignty. … Israel will not hesitate to respond to any attempt to harm IDF soldiers,” military spokesman Lieutenant-Colonel Peter Lerner said in a statement.
Hamas blamed Israel for the escalation and said that while it wanted calm, it would respond to Israeli actions. It did not immediately comment on the sniper fire.
The Israeli military said one of its soldiers, a member of a Bedouin unit, had been seriously injured.
More than 2,100 Palestinians, most of them civilians, were killed in seven weeks of fighting, according to the Gaza Health Ministry. Sixty-seven Israeli soldiers and six civilians in Israel were killed.
Material for this report came from Reuters, AFP and AP.