Even when the Israeli-Egyptian border is fully sealed, the threat of infiltrations will continue, IDF Chief of the General Staff Lt. Gen. Benny Gantz said Sunday.

While touring the southern border — where an Israeli soldier was gunned down Friday by terrorists, three of whom were killed — Gantz said that despite the “tremendous efforts” made to close the border, it will continue to present a challenge to Israel.

About 200 kilometers of a 240-km. stretch of fencing has been constructed in an accelerated project. The remaining 40 or so km. — in the  Har Harif area where Netanel Yahalomi was killed on Friday, and in a stretch near Eilat — is set to be completed by the end of the year or early 2013, the Knesset’s Foreign Affairs and Defense Committee was told recently.

Yahalomi, 20, was the sole Israeli fatality. He was shot in the head when the terrorists opened fired at his artillery force, which was securing work on the border fence in the Har Harif area, while also looking after a group of African migrants that had been stopped at the fence.

A second soldier, who was wounded in the stomach during the incident, was in stable condition at Soroka Medical Center in Beersheba on Sunday.

“We are combat soldiers who protect the borders. Clashes take place and anybody who chooses to serve in a combat unit knows that such things can happen,” said Gantz in a meeting with soldiers and officers from Yahalomi’s unit. “Netanel did his duty to its fullest. He initiated contact with the enemy, fought bravely and died — any one of you could have been in his place. I am sure that if he was here, he would say that we have to carry on with the mission.”

Ansar Jerusalem, a shadowy group inspired by al-Qaeda and based in Egypt’s Sinai Peninsula, claimed responsibility for Friday’s attack, and linked it to the video denigrating the Prophet Muhammad that has sparked protests across the Muslim world.

In a statement posted on militant forums late Saturday, the group said that the gunmen were Egyptian. It said the operation was a “disciplinary attack against those who insulted the beloved Prophet.” The low-budget film was produced in the United States. The group said three gunmen had crossed the border into Israel early Thursday and remained hiding until midday Friday, when they saw and attacked an Israeli patrol.

A preliminary IDF probe revealed that the gunmen exploited the presence of the group of African asylum-seekers — to whom several of the Israeli soldiers were offering basic humanitarian assistance — in order to approach the border.

The IDF has since ordered the soldiers to exercise extra caution along the border.