Three people were killed and several others injured, some seriously, said Mahmud Bassal, a civil defense spokesman, adding that the deaths resulted from a drone attack in Rafah in southern Gaza.
The local hospital said it had received three bodies and 15 injured people, one of whom later died.
In a separate attack on Khan Yunis, also in southern Gaza, another person was killed.
The Israeli military told AFP it had "struck terrorists" and that further information would be provided later.
More than 1,500 people are reported to have been killed in Israeli attacks over the past year since a formal ceasefire in Gaza.
