"Gunmen opened fire at the army soldiers at Abou Sokkar checkpoint in southern Arish city in North Sinai," the sources added, noting the assailants are believed to belong to hairline Jihadist groups in the peninsula.
Another 21-year-old army soldier was killed earlier Thursday by a Jihadist group who launched an attack on the military guards securing a police club at Masa'eed district in Arish.
Meanwhile, The Egyptian authorities decided Thursday to close Rafah crossing point bordering the Palestinian Gaza Strip indefinitely.
The attack comes a day after some 525 people were killed and 3, 717 others injured in the "dispersal operation" against pro-Morsi sit-ins in Cairo and Giza, as well as in relevant clashes in other governorates.
After Wednesday's events, Egypt has announced a state of emergency for one month and imposed a curfew in several governorates, including Cairo, Alexandria, and North and South Sinai.