The Palestinians said a family of eight was killed in a strike that destroyed their home. Israel's missile defence system again intercepted rockets fired by militants at the country's heartland.
Military spokesman Lieutenant Colonel Peter Lerner said Israel struck more than 320 Hamas targets, focusing on underground tunnel networks and rocket launching sites. That brought the total number of targets hit to 750 in three days of the massive offensive. At least 75 Palestinians have been killed.
Mr Lerner said Israel has mobilised 20,000 reservists for a possible ground operation into Gaza, but for the time being Israel remained focused on maximising its air campaign. A ground invasion could lead to heavy civilian casualties on the Palestinian side while putting Israeli ground forces in danger.
Neither side is showing any sign of halting their heaviest fighting since an eight-day battle in late 2012. Israel says Hamas must cease rocket fire from Gaza for it to consider a truce. Militants have fired hundreds of rockets, striking across the length of Israel and disrupting life across the country. No one has been seriously harmed as the Iron Dome defence system has intercepted at least 70 of the projectiles destined for major population centres.
Mr Lerner said: "The ground option needs to be the last option and only if it is absolutely necessary."
Palestinian medical officials said one strike hit a home in the southern Gaza city of Khan Younis, killing eight members from the one family.
The Israeli military also said it struck a car in Gaza carrying three Islamic Jihad militants involved in firing rockets. The militant group confirmed its men were killed in the strike. At least 20 civilians have been among the 75 deaths reported by the Health Ministry in Gaza, though the exact number is not known.