An Egyptian army officer and three soldiers were killed on Thursday when a bomb planted by suspected Islamist militants exploded near Rafah, a town on the border with the Gaza Strip, the army said in a statement.
Egypt is battling an increasingly brazen insurgency in the Sinai Peninsula that has killed hundreds of police officers and soldiers since the army toppled Islamist President Mohamed Mursi in 2013 after mass protests against his rule.
President Abdel Fattah al-Sisi has said militancy poses an existential threat to Egypt, the most populous Arab country.
No group immediately claimed responsibility for Thursday’s blast, but Islamic State’s Egyptian affiliate, Sinai Province, has launched similar attacks in the past.
Sinai Province recently claimed a bombing that heavily damaged the Italian consulate in Cairo and earlier this month attacked several military checkpoints in North Sinai, in what was the fiercest fighting in the region in years.