Egyptian soldiers on Gazan border (file)
Egyptian soldiers on Gazan border (file) Abed Rahim Khatib/Flash 90

Egyptian soldiers were caught on tape Saturday brutally gunning down a mentally ill Palestinian man who waded in the water from Gaza into Egyptian territory - but world leaders have been silent on the killing, in stark contrast to the common condemnation of IDF security measures against actual terrorists.

The victim, 28-year-old Ishak Khalil Hassan, hails from the Gaza City neighborhood of Zeitoun. Reports from Gaza show the man was known to be suffering from mental illness.

Al-Jazeera aired footage of Hassan walking naked into the Mediterranean Sea on the Gaza border with Sinai, and crossing through a wire fence into Egyptian territory. Then, before he could reach the shore and despite the clear lack of any security risk posed by the nude man, the soldiers are seen gunning him down still in the water.

In the video a person on the beach is seen signaling to Egyptian security forces, trying to get them to stop repeatedly shooting the man, but it is too late and Hassan's body is seen floating in the sea before being washed onto the shore.

"The shocking images aired by media outlets showing the death of the mentally disturbed young man by the Egyptian military mere meters from the border at Rafah testifies to the level of cruelty of those who carried it out and show that this was a cold-blooded execution," said the interior ministry of the Hamas terrorist organization in a statement.

"This is a reprehensible act that goes against all humanitarian laws and conventions," it added, demanding the Egyptian military investigate the incident. Hamas said Hassan's body remains in Egyptian hands.

Ironically, Hamas continues to hold Avraham Mengistu, a mentally ill Israeli who entered Gaza last September.

Angry Gazans also responded to the disturbing imagery on social media Saturday, harshly criticizing the Egyptian army.

The lack of international condemnation on Egypt's actions brings to mind the apparent double-standard in the lack of condemnation over Egypt establishing a massive buffer zone in southern Gaza, a project that began in October 2014.

The operation has involved occupying a large swath of land at least one kilometer deep (over half a mile) along the 14-kilometer (9-mile) border, evicting thousands of Gazans, destroying their homes and mosques, and recently even creating a border moat - but the world has remained largely silent.