In addition to the six dead, "a certain number have been injured" after an airstrike that targeted a police station in the Hamas-controlled area.
Shifa Hospital in Gaza City confirms that it has received six bodies, including a child born in 2011.
An AFP correspondent at the scene saw at least three bodies wrapped in white cloth.
An Israeli military source tells AFP that the army targeted "Hamas terrorists" in the area.
A ceasefire has been in place in Gaza since October last year, but Israel says it reserves the right to strike targets it deems a threat. Despite the ceasefire, Israel attacks the Gaza Strip on a regular basis.
