The Israeli military said it was looking into the reports.
The bodies of 15 people killed in the strike were brought to Kamal Adwan Hospital, its director Hussam Abu Safia told reporters.
He said 35 wounded people, most of them children, were being treated at the hospital.
Last week, the Gaza health ministry said Israeli troops had stormed the hospital, while the Israeli military said it was operating around it.
Since October 6, the military has conducted a sweeping air and ground assault in northern Gaza, particularly in the areas of Jabalia, Beit Lahia and Beit Hanoun, in what it describes as an operation to prevent Hamas militants from regrouping.
In a statement issued earlier today, the military said it had carried out several ground and air strikes in Jabalia over the past day, killing around 40 militants.
Tens of thousands of Palestinians have been forced to flee northern Gaza since the onslaught began, while the civil defence agency has reported hundreds of deaths.