Israeli forces beef up their presence on the Israeli-Gaza border Sunday -- with armored vehicles and helicopters.
The military says it is focused on destroying missile stockpiles and a vast tunnel system built by Hamas.
At least 60 Palestinians were killed by Israeli shelling on Sunday in a Gaza neighborhood.
13 Israeli soldiers were also killed.
In Gaza, an air strike hit a car and killed two people.
Three family members were killed when their house was bombed.
Palestinian President Mahmoud Abbas has accused Israel of carrying out a massacre, as the death toll for the 13-day conflict topped 400.
Israel has accused Hamas of using civilians as human shields by launching rockets from residential areas.
