The Israeli army is probing a February attack on a Doctors Without Borders (MSF) aid shelter in a so-called "humanitarian" zone in Gaza.
The incident killed two people and left seven injured, British broadcaster Sky News reported.
The media outlet said the site had been housing 64 people, among them MSF drivers and their relatives.
The Israeli military said it was carrying out an "examination" of the 20 February episode following an investigation by Sky.
It claimed its troops "fired at a building that was identified as a building where terror activity is occurring", although the army had not offered proof for the allegation, Sky said.
"After the incident, reports were received of the death of two uninvolved civilians in the area," the army reported.
"The [army] regrets any harm to civilians and does everything in its power to operate in a precise and accurate manner."
According to the military, an investigation has begun.
MSF said it "refutes any allegations of terror activity occurring in MSF-run structures".
"It is a civilian space, and this shows that nowhere is safe," it added.
The humanitarian group said the shelter was "used by humanitarian personnel and their family members" and had displayed an identifying MSF flag, while the Israeli authorities had been informed.
The MSF facility is situated in Al-Mawasi, an area in the south of Gaza which the Israeli military has claimed is a "humanitarian" zone.
Sky said the evidence and experts it had spoken to indicate the shelter was hit by a round from an Israeli tank.
The broadcaster quoted a witness as saying they heard "loud noises" sounding like the track of a tank.
"The loud noises were getting louder as the tanks were getting closer to our shelter… and by the time I got back to the designated place… the whole building was shaking violently," the witness said.
Two other witnesses reported hearing tanks and gunshots.
Jihad Al-Agha recounted seeing "fire light up" inside the building and he believed the tanks were about 20 metres from his location. Abu Hasmed Al-Aghar reported going "towards the sound of women and children's screams", adding that he "saved them from the inside, the fire".
Based on images secured by Sky, Amael Kotlarski, weapons team manager at intelligence company Janes, said: "I'd say whatever came through the window, came from an upward angle and detonated either on impact with the roof, or air bursted just below it.
"Given the damage on the roof, I'm inclined to the latter rather than the former."
Chiron Resources director Chris Cobb-Smith, who was as an artillery officer in the British army, indicated a tank round had been used.
"It's difficult to draw definitive conclusions merely from imagery however I believe the damage is the result of a tank round being fired directly into the building," he said.
"Only a tank shell would cause that type of damage. Only a tank would have the ability to launch a projectile at that range and at that trajectory and bearing."