Israel said on Thursday that its aircraft struck a Hamas military site in the Gaza Strip overnight after balloons carrying firebombs were launched from the Palestinian enclave.
After the air strike, Israel's military said there had been two "launches" – probably rockets – from the Gaza Strip toward Israel.
No further details were immediately available.
The air strike hit targets within what Israel's army called a Hamas military compound in the northern Gaza Strip. There had so far been no reports of injuries.
It was unclear if the firebombs caused any damage within Israel.
Palestinians in Gaza have been regularly sending balloons carrying firebombs over the border fence to damage Israeli property and have in the past succeeded in setting fire to large areas of farmland.
An Egyptian and UN-brokered ceasefire between Israel and Hamas, the movement that runs the Gaza Strip, had led to relative calm around Israel's April 9 election.
But on Tuesday, Israel reduced the offshore fishing limit it imposes for vessels operating out of the blockaded strip after a rocket was fired from the territory by Palestinian militants.
Fishing boats came under Israeli naval fire early on Tuesday, the fishermen's union said, after the military said they breached the fishing boundaries.
Israel had extended the fishing limit to 15 nautical miles in some areas from April 1 as part of measures intended to calm a flare-up of violence with Hamas before the April 9 Israeli general election.
The Gaza fishermen's union said the limit was then set at 15 nautical miles in the south near the Egyptian border, at 12 off central Gaza and at six in the north near the Israeli border.
Israel and Palestinian militants in Gaza have fought three wars since 2008.