The Israeli occupation army said it pounded Hamas targets in the Gaza Strip early Wednesday, while dozens of rockets and mortar shells were fired from the Palestinian enclave.
The strikes targeting Hamas's military wing, the Ezzedine al-Qassam Brigades, were more intense than in previous sorties to convey the message "we will not allow this situation to continue," Israeli occupation military spokesman Jonathan Conricus told reporters.
The latest spike in tensions follows weeks of deadly protests and clashes along the Gaza-Israel border as well as the worst military escalation last month since the last Israeli offensive on Gaza in 2014.
It comes as US President Donald Trump's special envoy Jason Greenblatt and adviser Jared Kushner visit the region to discuss issues including the Palestinian-Israeli peace process.
Israeli planes initially targeted three Hamas military positions overnight in Gaza in response to kites and balloons carrying incendiary and explosive devices launched into Israel from the Palestinian territory, the occupation army said.
"They may look like toys but I can assure they are not toys, they are weapons intended to kill and to inflict damage," Conricus said.
He said that so far Israel had sought to warn off those launching the airborne devices but that could change.
"Hamas and other terrorists, but mainly Hamas" hit back after the first air raids with more than 45 rockets and mortar rounds fired from Gaza towards Israel, seven of which were intercepted by the Iron Dome missile defence system, he added.
Three more landed inside Israel, he said, but did not account for the remainder.
In response, Israeli planes carried out more raids against 25 "terror objectives" including an underground training compound, according to the army.
Gaza medical sources said that five people were lightly injured in the strikes.
In a joint statement, the military wings of Hamas and allied militant group Islamic Jihad said they had "targeted seven Israeli military positions near Gaza... in response to continued Israeli aggression against resistance sites in Gaza."
Early Wednesday afternoon, Israeli aircraft fired near Palestinians in southern Gaza launching incendiary kites, and later in the day, aircraft fired near Palestinians attempting to do the same in northern Gaza, a military spokesman told AFP.
Tensions have soared in Gaza since mass protests and clashes broke out along the border on March 30. At least 132 Palestinians have been killed. There have been no Israeli fatalities.
Palestinians are demanding the right to return to the homes their families fled or were expelled from during the 1948 war surrounding the creation of Israel.
UN Secretary General Antonio Guterres has warned that Gaza is close to the brink of war.
Israel launched three military campaigns against Gaza since 2008. Peace talks between Israel and the Palestinians have been stalled since 2014.
On Tuesday Greenblatt and Kushner met with Jordan's King Abdullah II in Amman to discuss the Palestinian-Israeli peace process during a regional tour that will also take them to Israel, Egypt, Qatar and Saudi Arabia.
Trump's controversial December decision to recognise the disputed city of Jerusalem as Israel's capital prompted Palestinians to freeze all contacts with US officials.
*This story was edited by Ahram Online.