Militants killed 21 border guards on Sunday in the attack on the checkpoint in Al-Wadi Al-Gedid governorate, more than 500 kilometers from here, said army spokesman Mohamed Samir. (Agencies)
The border guards were killed during an exchange of fire with the unknown gunmen which lead to an explosion in the checkpoint's ammunition storage, Samir said, adding forces later seized and defused two car bombs before they exploded.
Al-Wadi Al-Gedid is a large governorate that borders both Libya and Sudan.
Samir also said that some "terrorists" were killed during the exchange of fire.
The attackers, armed with rocket-propelled grenades, took the soldiers by surprise, a military source told the state-run news agency MENA.
The attack, reportedly took place at the time of Iftar (breaking the fast meal in Ramadan), resembling an earlier attack in August 2012 in which 16 soldiers were killed by militants in Sinai.
The Egyptian government on Sunday declared three days of mourning in memory of the fallen soldiers.
Saturday's attack is the biggest such single act of violence against army or police since last August when 25 police conscripts were killed near Sinai's Rafah.
Militant attacks targeting police and military have been commonplace since the ouster of Islamist president Mohamed Morsi by the army last summer amid mass protests against his year-long rule.
Militants killed 21 border guards on Sunday in the attack on the checkpoint in Al-Wadi Al-Gedid governorate, more than 500 kilometers from here, said army spokesman Mohamed Samir.