At least 15 Egyptian troops were killed on Saturday at a checkpoint in a western region of the country.
Three of the attackers were also killed in the clash in Wadi el-Gedid, and five other Egyptian troops were wounded.
Insurgent attacks on government troops have picked up since former Egyptian President Mohammed Morsi’s government was toppled by the military.
The violence takes place as Egypt faces pressure to control its border with Gaza. Egypt’s government sought to negotiate a ceasefire agreement between Hamas and Israel this week, but it was broken.
Hamas has demanded an easing of the blockade on Gaza by both Israel and Egypt. Meanwhile, Israel is stepping up its siege in Gaza, with the death toll reaching upwards of 300 – including mostly children, according to a report.