Nineteen Palestinians were killed in the Gaza Strip and four people were killed in Israel on Sunday, Palestinian and Israeli authorities said, during the most serious escalation since a 2014 war.
Israel carried out a series of strikes in response to rocket barrages fired from the Hamas-run territory.
In total 19 Palestinians were killed by Israeli strikes in Gaza on Sunday, the enclave’s health ministry said.
The ministry said among those killed on Sunday were a pregnant woman and a four-month-old baby. The Israeli military declined to comment on the claim.
At least six of those killed were confirmed to be militants affiliated with the Palestinian territory’s leaders Hamas or the allied Islamic Jihad group.
On the Israeli side four civilians were killed as Hamas and Islamic Jihad fired barrages of rockets and at least one anti-tank missile from the enclave, Israeli authorities said.
Three of the dead were identified by authorities as Israeli citizens, with the nationality of the fourth not announced.
Israeli targets included internal security headquarters in the Palestinian enclave, an interior ministry statement said.
The building in Gaza City was destroyed, the statement said.
Rocket fire and Israeli strikes continued Sunday evening.