Israel pounded Gaza, destroying a tower block that housed media organisations and which it said had militant assets, while Palestinian rocket salvoes hit Tel Aviv on Saturday, with no sign of an end to almost a week of fighting, APA reports quoting Reuters.
The death toll is rising from the worst escalation since 2014 and diplomacy has so far failed to quell it.
Israel's military brought down a 12-storey block in Gaza City that housed the U.S. Associated Press and Qatar-based Al Jazeera media operations, as well as other offices and apartments, leaving a huge heap of broken masonry.
Israel gave advance warning of the strike so it could be evacuated and said later the building contained military assets of Hamas, the Islamist group that runs Gaza.
The United States told Israel "that ensuring the safety and security of journalists and independent media is a paramount responsibility," White House Press Secretary Jen Psaki said.
The AP and Al Jazeera strongly condemned the attack.
Palestinians say at least 139 people, including 39 children, have been killed in Gaza since the conflict erupted on Monday.
Israel has reported 10 dead, including two children.