Twenty-six Egyptian soldiers were killed or wounded on Friday in attacks on checkpoints in the Sinai Peninsula where the Daesh group is conducting an insurgency, the military said.
Earlier, an official security source told Xinhua that at least 10 Egyptian soldiers were killed and 20 others injured in two vehicle explosions and a later shooting at army checkpoint in North Sinai's city of Rafah.
No group has claimed responsibility for the attack.
President Abdel Fattah al-Sisi describes militancy as an existential threat to Egypt, which has increasingly seen attacks move beyond the war-torn Sinai Peninsula and deep into the mainland, often targeting Christians.
Security officials told the Associated Press that Friday's attack targeted a military compound in al-Barth, south-west of Rafah, where about 60 soldiers were based.
At least ten Egyptian soldiers including a colonel were killed in a suicide bomb attack on an army checkpoint in northern Sinai. It also posted photographs of five alleged assailants dressed in uniforms.
The area was also the site of fierce battles in the spring between the tribesmen and militants. About 100 Copts have been killed in such attacks in mainland Egypt since December.
In January, eight policemen were killed in the city of el-Arish in a auto bomb explosion.
Ambulances rushed into the scene, and the security forces were combing the nearby roads in search of perpetrators.
The officials initially put the death toll at 10.
"We considers it a criminal, terrorist, and coward attack that doesn't target Egypt only, but the security and stability of the entire Arab nation", Hamas' spokesman Fawzi Barhoum said. Hundreds of police and army personnel were killed since then.
Three Egyptians who worked at a building site in the Western Desert were killed by an airstrike from a military aircraft in what appears to have been an accident, their family members said Friday.