At least six other troops were wounded in the attack in Sheikh Zuweid, in the northern part of Egypt's Sinai Peninsula.
Officials added that security personnel killed three militants in the firefight and the area was reinforced.
Violence and instability in the region intensified after the 2013 military ousting of Mohammed Morsi, amid nationwide protests against his brief rule.
The militants have attacked security forces, minority Christians and those they accuse of collaborating with the military and police.
Cover image: Distant houses in the Sinai Peninsula (Library picture: Yakov Oskanov/Alamy Stock Photo).