Israeli air and tank strikes hit Hamas targets in the Gaza Strip late on Friday, Israel’s army said.
It said they were in reprisals for firebombs suspended from balloons that floated into Israel from the enclave.
The navel defence system used by Hamas, underground infrastructure and observation posts were among the positions struck, the Israeli army said.
A pregnant woman and a 3-year-old child were injured in the attacks and taken to hospital, the Palestinian Red Crescent said.
Dozens of blazes have been reported this week in southern Israel, as makeshift firebombs attached to bunches of balloons or kites set agricultural fields and scrubland alight.
In response, Israel has closed its cargo crossing with Gaza and reduced the territory’s permitted coastal fishing zone.
The attack on Friday, was the sixth such night-time operation this week.
Hamas on Thursday condemned Israel’s attacks on Gaza and its sanctions as “dangerous and aggressive behaviour”, warning the country of consequences it will bear.
The militant Islamist group, which controls the Gaza Strip, has fought three wars against Israel since 2008.
Despite a truce last year backed by the UN, Egypt and Qatar, the two sides clash sporadically with rockets, mortar fire or incendiary balloons.
The Gaza Strip has a population of two million, more than half of whom live in poverty, according to the World Bank.
Palestinian analysts say fire from Gaza is often intended to pressure Israel into approving the transfer of Qatari financial aid into the territory.
