Israeli warplanes have struck Hamas strongholds in Gaza as retribution for a wave of unmanned balloons equipped with incendiary devices released on the wind from the Palestinian enclave.
The Israeli military said the sites included weapons manufacturing sites and intelligence-gathering facilities.
There were no reports of injuries from the airstrikes in southern Gaza Strip on Saturday.
Blaming Hamas, the military said it considers "any kind of terror activity with great severity and will continue operating as necessary against attempts to harm its civilians".
Palestinian groups resumed launching flammable balloons recently, and Hamas said it's encouraging the shootings, charging Israel of not honouring an unofficial truce meant to improve the economy of the narrow enclave.
In trying to bolster the Egyptian and UN-mediated truce, Hamas halted the regular weekly protests along Gaza-Israel fence last month.
Earlier this week, a senior Hamas official said the balloons were a signal to Israel to accelerate the informal "understandings" meant to ease the crippling blockade on Gaza.
The official, Khalil al-Hayya, said the balloons are being launched by disgruntled individuals, not Hamas. But he said his group was "satisfied" with the launches and is ready to send more "if the occupation doesn't pick up the message."
Al-Hayya said Hamas expects Israel to allow in more medical supplies, unlimited trade between Gaza and the world, help create more jobs and extend Qatari payments for electricity and poor families.
Israel and Egypt imposed the blockade when Hamas, viewed as a terrorist organisation by the US and most of the West, rose to power in a violent takeover in 2007.
– with AAP