The unarmed 28-year-old Palestinian who was shot dead by Egyptian guards after he swam in from the Gaza Strip on Thursday was not mentally disturbed, according to his father.

video showed Ishaq Khalil Hassan swimming naked in the Mediterranean Sea and then crossing into the Egyptian side through a barbed-wire fence.

Palestinian security officers can be seen shouting at the Egyptian guards in a watch tower to stop them from shooting at Ishaq before he was shot.

“My son was neither mentally disturbed nor crazy," Ishaq's father Khalil Hassan told Al Jazeera.

"He had suffered an injury to his legs during the 2008 Gaza war and he was quite stressed out because he was in a lot of pain and could not travel to Egypt to continue his treatment."

Ishaq Hassan [Al Jazeera]

The family had managed to send Ishaq for treatment in Egypt but the permanent closure of the Rafah crossing between Gaza and Egypt has made it almost impossible for any Palestinian from Gaza to pass through it, Khalil said.

"My son was trying to improve his life and was interested in studying engineering. He was taking English language lessons so he could enrol at a college."

Khalil stressed that his family, including his late son, was not involved in politics of any kind.

The Rafah crossing point between Egypt and Gaza is shut throughout the year and is opened only about three or four times a year by Egypt.

The only other crossing point for Palestinians out of Gaza is the Erez crossing between Israel and Gaza.

The Israeli government allows only limited numbers to cross, mainly for humanitarian and business reasons.

Swairjo Thoalfikar, a Gaza-based Palestinian writer and political analyst, told Al Jazeera that the killing of Ishaq was part of the "Egyptian army's policy that deals with the Palestinians in Gaza on a shoot-to-kill basis".

"Egypt considers Gaza an enemy entity while Israel is a friendly state, which explains why the Egyptians have a policy of shoot-to-kill against Palestinians if they cross the borders illegally or mistakenly," said Thoalfikar.

He added that Egypt should treat the Palestinians "as brothers, not as enemies".

Maha Hussaini a spokesperson for the Euro-Mediterranean which monitors Human Rights in Gaza told Al Jazeera that “Egyptian soldiers could have arrested him or perhaps used non-lethal violence to stop him.

The Egyptian government has not commented on the incident. Al Jazeera has tried to reach several Egyptian government officials but all calls have gone unanswered.

Iyad al Buzum, spokesman for the Palestinian Ministry of Interior in Gaza, demanded an investigation into the killing and told Al Jazeera that it "is an act that must be condemned".

Ishaq was swimming close to local fishermen and was able to slip past the Palestinian security officials before they could stop him, said Buzum.

Follow Ali Younes on Twitter: @ali_reports

Source: Al Jazeera