Israeli military jets targeted sites linked to Palestinian Islamic Jihad in the Gaza Strip, hours after militants from the group fired more than 20 rockets into Israeli territory.
The exchange came after a Palestinian news agency posted graphic footage showing an Israeli Army bulldozer dragging the body of a Palestinian man - who Israel said was part of a "terror squad" - who was killed as he placed an explosive device along the border fence.
The sudden flare-up followed weeks of relative quiet as Egypt attempts to broker a long-term truce between Israel and Hamas, the militant Islamist faction that rules the Gaza Strip. Israel and Hamas have fought three wars in the past decade, and there have been many other flare-ups in violence.
It also comes a week before Israelis return to the polls for a third general election in less than a year. Prime Minister Benjamin Netanyahu's handling of the long-running Gaza situation came under sharp criticism over the weekend.
The Israeli military said more than 20 projectiles and rockets were fired from Gaza today. Most were intercepted by the Iron Dome aerial defence system. Videos shared on social media showed civilians in the cities of Ashkelon and Sderot crouching for cover as warning sirens blared in most of the Israeli communities that surround Gaza.
Emotions in Gaza were high after the video clip, filmed by a photographer working with the West Bank-based news agency al-Hadath, showed the Israeli military bulldozer scooping up the body. An army tank is seen accompanying the bulldozer in the video, which was shared widely on social media.
Hamas and the Palestinian Islamic Jihad issued statements condemning Israel's actions and swore revenge. The dead man was identified as Mohammed al-Naem, a member of the Islamic Jihad, the second-largest militant faction in Gaza after Hamas. Abu Hamza, a spokesman for the group's armed wing, the al-Quds Brigades, said Israeli military vehicles had entered Gaza, and he warned that there would be consequences.
Hamas spokesman Fawzi Barhoum said Naem was "defenceless" and was killed deliberately.
"The abuse of his body right before the eyes of the entire world is a heinous crime that can be added to the other crimes against our people," Barhoum said.
Islamic Jihad took responsibility for the rocket fire, saying it was in response to Naem's killing.
The video also drew criticism inside Israel. Human rights groups called on the military to investigate the incident.
Adalah, the Legal Centre for Arab Minority Rights in Israel, said in a letter to the army's legal representative that the actions "depicted in the video were viewed as war crimes and blatant violations of international criminal law, and international human rights and humanitarian law."
Defence Minister Naftali Bennett defended the army's actions, saying on Twitter that it had "killed a terrorist and collected his body."
"This is how it should be done, and this is how it will be done," he wrote.
Some far-right leaders, including Bennett before he became defence minister, have called for Israel to respond with greater force to rocket fire and other violence from Gaza.
There has been fierce criticism of what appears to be an attempt by Netanyahu to reach a long-term understanding with Hamas.
Avigdor Liberman, Israel's hawkish former defence minister, revealed that Netanyahu had sent the head of Israel's Mossad intelligence agency to Doha, Qatar, this month to ask the gulf state to continue sending emergency funds to the impoverished Gaza Strip.
And last week, Israel announced steps to increase the number of entry permits for day labourers from Gaza and enlarge the fishing zone for Palestinian fishermen.