Islamist group Hamas on Saturday condemned the fatal shooting by Egyptian border guards of what they said was a Palestinian minor on the Gaza border.
"We condemn the killing (Friday) of the child Zaki al-Houbi by Egyptian army gunfire on the borders, we consider what happened as a dangerous development and excessive use of force," the Islamist organisation said in a statement.
"What happened is not appropriate to neighbourly relations between brothers."
An Egyptian security official said that troops opened fire on Gazans who had illegally crossed into the Egyptian Sinai, where the army has created a buffer zone to prevent the movement of militants.
"Soldiers charged with protecting the frontier fired at six Gazans, of whom three succeeded in returning to Gaza while three were arrested. One was probably hit by the fire," an official said.
Gaza emergency services spokesman Ashraf al-Qudra said that Houbi was 17 years old.
He was killed in the Gaza frontier town of Rafah by Egyptian soldiers firing from across the border, Qudra said.
The border troops shot the youth "in the back and the bullet settled in the heart. He died on the spot," he told AFP.
He was the first Palestinian "to have been killed in a long time" along the border between the Gaza Strip and Egypt, according to Qudra.
An eyewitness told AFP that Houbi and three others scaled a concrete wall on the border hoping to find work on the Egyptian side.
His mother, Sarah al-Houbi, 35, said that he had "left home to look for work" adding that her husband was unemployed and the family stricken by the poverty rampant in Gaza.
She said that he was not a member of any militant group and had tried several times to get into Egypt but was sent back each time.
Egypt announced on Tuesday that work to double the width of a buffer zone along the Gaza border would begin next week to prevent militants infiltrating from the Palestinian enclave.
Construction of the 500-metre (550-yard) buffer zone along 10 kilometres (six miles) of the border comes after an October 24 suicide bombing that killed 30 Egyptian soldiers. Some 800 homes are being demolished in the process.
After that incident, Egypt declared a three-month emergency in parts of North Sinai -- a remote but strategic region bordering Israel and Gaza -- and closed the Rafah border crossing for two months.
The crossing is Gaza's only gateway to the outside world not controlled by Israel.
Egypt suspects Palestinian militants of aiding jihadist attacks against its security forces, which have increased since the ouster of Islamist president Mohamed Morsi last year.
The Egyptian army has also stepped up the destruction of tunnels from Gaza it says are used to smuggle arms, food and money by Palestinian militant group Hamas which controls the territory.
Cairo says it has destroyed more than 1,600 tunnels since Morsi's ouster.
Meanwhile, the Israeli navy opened fire early Saturday on two Palestinian boats off the southern Gaza coast, wounding a fisherman, Gaza medical officials said.
An Israeli military spokeswoman told AFP that the fishing boats were headed for Egyptian waters and suspected of involvement in smuggling. She said that a naval patrol fired at the boats after they ignored warning shots and orders to turn back.
Under the terms of an agreement with Israel, Gaza's fishermen have the right to trawl the waters up to six nautical miles off the coast.
*This story was edited by Ahram Online