Five Palestinian children were among 25 people killed in Israeli air strikes on Gaza early Thursday, medics said, with most of the bloodshed in the southern city of Khan Yunis.
The deaths bring to 76 the overall number of Gazans killed since Israel launched Operation Protective Edge early on Tuesday to halt cross-border rocket fire.
In one attack, a five-year-old boy was killed when an Israeli missile struck the northern Gaza town of Beit Lahiya, emergency services spokesman Ashraf al-Qudra told AFP.
The majority of deaths took place in Khan Yunis with a strike at around 1:00am (2200 GMT) hitting a coffee shop where people were watching the World Cup semi-final between Argentina and the Netherlands.
Eight people were killed and at least 15 wounded.
An hour later, Israeli warplanes struck two houses elsewhere in the city, killing four women and four children, Qudra said.
A 19-year-old man also died in a separate strike on the southern city in the late morning.
In central Gaza, a man was killed in a strike on Nusseirat refugee camp.
Meanwhile in the north, a missile hit a car in western Gaza City shortly after daybreak, killing three.
And another air strike on a car in the town of Jabaliya killed three men, medics said.
Separately, a man who was badly wounded in a raid east of Gaza City a day earlier died of his wounds.
His death raised Wednesday's toll to 30 people. On Tuesday, the first day of the operation, 21 people were killed.
The army said it had hit more than 300 targets overnight, raising the total number of strikes just over 48 hours to 750, in Israel's largest military operation in Gaza since November 2012.
On Tuesday, 117 rockets fired by Gaza militants struck Israel, and 29 were intercepted by the Iron Dome anti-missile system.
Another 90 rockets hit Israel on Wednesday, and 24 were intercepted.
On Thursday, 15 rockets struck Israel, while another seven were intercepted, army figures show.
There have been no Israeli deaths so far, but Hamas has launched waves of rockets across central Israel that have triggered sirens in cities as far from Gaza as Tel Aviv, Jerusalem, and Haifa.