A video making the rounds on WhatsApp on Monday evening purports to show an IDF sniper shooting a Palestinian who came near the Gaza border fence.
It is unclear where on the Gaza border or when the video was filmed, and the IDF has yet to confirm its authenticity.
The video, which was filmed through the lenses of a rifle's sights or binoculars, shows several Palestinians close to the border fence.
A commander is heard instructing the sniper, telling him "When he comes out, you get him. Do you have a bullet in the barrel? Are you on him?" After the sniper responds in the affirmative, the commander tells him "Go."
The sniper tells the commander that he cannot shoot, because the barbed-wire near the fence was in the way.
Several moments later, the commander speaks again, this time telling the sniper to hold fire after he spots a child.
Later two snipers are heard discussing who was on which Palestinian, following which a single shot is heard and one Palestinian is seen falling to the ground, with dozens of others immediately converging on him.
"Wow, what a video! YES! Son of a b****," one of the soldiers is heard exclaiming. Another is heard commenting that "Someone was hit in the head."
At first glance, it appears the video was filmed by a soldier who wasn't shooting, but was alongside the snipers who were.
One soldier is heard whispering the cameraman "Film it, film it," with the filming soldier commenting "what a legendary video."
The video's release comes after more than a week of daily protests by Palestinians at the Gaza-Israel border in which 30 Gazans have been shot dead.
The IDF said the clip might have been filmed months ago.
In a tweeted statement, the IDF said: "With regard to the video of the soldiers at the Gaza Strip border - it was probably an event that occurred a number of months ago. The event will be investigated and examined thoroughly."
Ayman Odeh, the head of the Joint List of Arab parties, said it was "a clip that terrifies the soul, rejoicing over the taking of a life and what appears to be the execution of someone who endangered no one". He called for the shooter to be put on trial.
Israel has been warning Gazans for weeks not to approach the border fence. The IDF has stationed sharpshooters to enforce a no-go zone near the border fence and stop Palestinian attempts to breach the border during a Hamas-organized protest that has been called "The Great March of Return."
The protesters are reviving a long-standing demand for the right of return of Palestinian refugees to towns and villages from which their families fled, or were driven out, when the state of Israel was created.
Protest camps have sprung up a few hundred metres inside the fence. But large groups of youths have ventured considerably nearer, burning tires and hurling stones.
Haniyeh vows to 'return to Palestine'
Hamas leader Ismail Haniyeh renewed a pledge Monday that the marches would pave the way for a return of Palestinian refugees and their descendants to what is now Israel.
"We will return to Palestine, our villages and Jerusalem," Haniyeh said in a fiery speech at one of five protest camps set up along the border.
He stopped short of threatening a mass breach of the border, though another Hamas leader has done so in recent speeches.
The IDF has accused Hamas of using the protests as a cover for carrying out attacks and bringing infiltrators into Israel. It has said some of those at the border tried to damage the fence, planted explosives or hurled firebombs.
Meanwhile, Prime Minister Benjamin Netanyahu visited Sderot, an Israeli community near Gaza, and said Israel's top priority is its security.
"We have one clear and simple rule and we seek to express it constantly: If someone tries to attack you -- rise up and attack him," Netanyahu said. "We will not allow, here on the Gaza border, them to hurt us. We will hurt them."
Reuters contributed to this report.