GAZA CITY - Israeli warplanes pounded Hamas targets in the Gaza Strip early Wednesday in a new flare-up of hostilities that saw dozens of rockets and mortar shells fired from the Palestinian enclave, the army said.
A military spokesman said all targets belonged to Hamas's military wing, the Ezzedine al-Qassam Brigades, and the strikes were more intense than in previous sorties.
"We struck at a greater intensity, with the intended message for Hamas to understand that we will not allow this situation to continue," 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 a 2014 war.
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 devices launched into Israel from the Palestinian territory, the army said.
Palestinians are sending kites dangling coal embers or burning rags across the Gaza border to set fire to farmland and forests.
No one has been hurt by the fires, but thousands of acres of land already parched after a dry winter have been burned by flames stoked by Mediterranean winds, causing millions of dollars in damage.
"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.
"We have warned verbally, we have fired various munitions in close proximity to (them), we have fired various munitions on various related supporting infrastructure and equipment, vehicles etcetera, related to efforts to launch kites -- that may not remain the situation," Conricus said in English.
"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.
Conricus said that more than 200,000 Israeli civilians live within range of the short-range rockets fired from Gaza.
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 lands and homes from which their families were ethnically cleansed, by Jews from Europe, during the 1948 war surrounding the creation of Israel.
The Gaza Strip is controlled by Hamas which Israel considers its bitter enemy.
Israel maintains the use of live ammunition is necessary to defend its borders and stop infiltrations. It accuses Hamas of seeking to use the protests as cover for attacks.
UN Secretary General Antonio Guterres has warned that Gaza is close to the brink of war.
The most serious military escalation since the 2014 war between Israel and Hamas last month raised fears of yet another full-blown conflict in the Palestinian enclave.
Israel said in late May it targeted some 65 militant sites in the Gaza Strip. It also said around 100 rockets and mortars fired from Gaza either exploded in Israel or were intercepted by air defences.
Israel and Hamas have fought three wars since 2008 and observe a tense ceasefire that is regularly shaken by hostile acts.
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 sparked anger across the Arab world and prompted Palestinians to freeze all contacts with US officials.