At least 22 Palestinians have been killed in a series of Israeli air strikes across northern and central Gaza, Hamas medical and civil defence officials have said.
They said five sites had been hit, including residential homes. A senior Hamas commander was among the dead, according to local sources.
The Israeli military said it had struck targets in Gaza in response to an incident earlier on Saturday, when it said an "armed terrorist" had fired at soldiers after crossing the Strip's so-called "yellow line" designating areas under full Israeli control. Hamas denied this.
Both sides have accused each other of violating the ceasefire deal agreed on six weeks ago.
More than 310 Palestinians have been killed in Israeli strikes since the ceasefire came into force, according to Gaza's health ministry.
