Ismail Haniyeh, who is widely known as the leader of Hamas, says that the US is responsible for the attack on the "Al Ahli" hospital, saying that Washington has given Israel "cover for the aggression", reports the BBC.
"The massacre in the hospital confirms the brutality of the enemy," Haniyeh said in a televised address.
He called on all Palestinians to "come out and face the occupiers" and called on Arabs and Muslims to organize protests against Israel.
The attack left over 500 people dead. Israel has denied involvement.
On the other hand, the US Department of Defense has stated that the US is providing security systems to Israel to eliminate the Palestinian group Hamas and "this does not mean killing innocent civilians" in Palestine.
"We are certainly giving Israel the security systems it needs to eliminate Hamas in Gaza... This does not mean killing innocent civilians," said Pentagon Deputy Press Secretary Sabrina Singh.
Her comments came in response to a question about reports of an Israeli attack on Al-Ahli Arabi Baptist Hospital in Gaza.
"I am aware of the reports, but I have nothing further to offer at this time," Singh said of the attack that left hundreds dead.