JERUSALEM – A shootout along the Israel-Egypt border on Friday, in which three Islamic militants and an Israeli soldier were killed, highlighted the growing threat posed by al-Qaida-inspired groups that have taken hold in the vast desert of the Sinai Peninsula.

The militants were heavily armed and wearing explosive belts when they infiltrated into Israeli territory and opened fire on soldiers protecting a team of workers building a border fence meant to buffer against just such attacks, the Israeli military said.

It said the troops quickly returned fire, killing the militants and preventing a major terror attack. During the exchange, Cpl. Netanel Yahalomi, 20, was shot in the head and later died of his wounds. Another soldier was moderately wounded.