At least ten soldiers were killed and 35 injured in a bomb attack in North Sinai on Wednesday.
A parked car blew up as an army convoy passed by on the road between Al-Arish and Rafah, a security source told state news agency MENA.
The soldiers were about to begin their vacation.
Some of those critically injured were flown to a military hospital in Cairo’s Maadi, Al-Ahram Arabic news website reported.
Preliminary examinations show a large amount of TNT explosives was used in the bomb, it added.
Troops and Apache helicopters have been combing the area for the perpetrators.
The attack is the bloodiest since mid-August when gunmen killed 25 policemen in an ambush on a security convoy in Rafah.
The restive peninsula, already suffering a security vacuum since the ouster of autocrat Hosni Mubarak, has seen a spike in militant activity since Mohamed Morsi’s ouster. Attacks on security and army targets in the Sinai region have killed over 100 since July.
Dozens of militants have been killed since the army began a campaign to flush out “terrorists” and seize or destroy arms caches in the Sinai region.