Ismail Haniyeh, a senior leader of Hamas and formerly its Prime Minister in Gaza, was taken to hospital on Wednesday evening, Channel 2 News reported.
There were no details as to what the reason for the hospitalization was, or what his condition is.
Senior members of Hamas, however, denied there was anything wrong with Haniyeh.
The officials said that reports of the leader’s hospitalization were nothing but “false rumors”.
Haniyeh’s son, Abd al-Salam Haniyeh, rejected the reports as well, saying his father had simply gone to the hospital to visit Gazans who were wounded in Israel’s recent attacks.
Reports of Haniyeh’s alleged hospitalization came hours after the Israel Security Agency (ISA, or Shin Bet) published a report on Hamas's use of public buildings as cover for operational activity.
The report quoted Hamas terrorists captured in Operation Protective Edge who admitted that the Hamas leadership in Gaza under Haniyeh is hiding out inside the Shifa Hospital in Gaza.
Reports of the Hamas leader’s hospitalization also came hours after he greeted thousands of Gazans in a central Gaza square in a massive “victory rally” following the signing of a long-term ceasefire with Israel.
According to the Ma’an news agency, in his speech, Haniyeh hailed the people of Gaza and the “resistance forces” for their steadfastness in the fight against Israel.
"Those whose blood was spilled and the martyrs were the fuel of this victory," Haniyeh said during the rally, emphasizing to the crowd of thousands that the resistance had been preparing for the battle for years.
"It is not possible to express this victory with words and speeches," he added, according to Ma’an.
"The victory is beyond the limits of time and place. This battle is a war that lacks a precedent in the history of conflict with the enemy," he said, stressing that the group was preparing for the "ultimate battle" for the “liberation of Palestine.”
"The war began with fire on Haifa and ended with fire on Haifa," he told the crowd.
"The Palestinians who couldn't celebrate Eid al-Fitr because of the fighting and because they were on the battlefield, today celebrate the celebration of victory," declared Haniyeh.
On Tuesday, several senior Hamas and Islamic Jihad leaders appeared in public shortly after the Gaza truce took hold, the first time they had done so since the conflict began on July 8.
Hamas has already said that any truce would be so as to plan the next terror war on Israel.