One civilian and an officer were killed in two separate attacks on Tuesday in the restive North Sinai, where the Egyptian army and militants have been at war for years.
The civilian victim died when a bomb-laden water truck, which attempted to storm a security camp located in El-Masaeed area of Al-Arish, exploded as camp guards opened fire at the truck.
The civilian casualty was a worker at an electricity facility adjacent to the camp. The driver of the truck was also killed in the operation, according to the interior ministry.
The operation left at least 42 army soldiers and two civilians injured, health ministry undersecretary for North Sinai Tarek Khater told Ahram Online.
Some buildings around the camp were damaged during the blast.
Meanwhile, in a town located south of Al-Arish, an officer was killed and three soldiers injured in an attack on an armoured military vehicle, Khater said.
Tuesday's attack on the security camp marks the first major terror operation against a security post in the restive peninsula since Islamist militants killed 30 soldiers and civilians at a security checkpoint in October.
In January, at least 26 people, including civilians and soldiers, were killed when a series of militant attacks, involving car bombs and mortar rounds, struck several army and police positions in North Sinai.
The government has enforced a sunset to dawn curfew in Al-Arish since the October blast.
Tuesday's attack comes days before an international investment summit scheduled to take place 13-15 March in Sharm El-Sheikh, South Sinai.
Egypt's army has been fighting a decade-long militant Islamist insurgency that has spiked since the ouster of president Mohamed Morsi in summer 2013.
Hundreds of police and army forces were killed in violent militant attacks.
Ansar Beit Al-Maqdis, an Islamist militant group, has claimed many of the attacks against the army and police in Sinai.
Since November Ansar Beit Al-Maqdis has sworn allegiance to Islamic State (IS) militant group, which has taken over vast areas of Syria and Iraq and now operates in Libya.
The army says it has intensified its operations against terrorists in the restive peninsula in recent months.
On Sunday, a military spokesman announced that forces have killed 70 suspected militants in North Sinai over the last week. He also said that 173 suspected militants were killed during February.
Egypt is also currently trying 213 alleged members of Sinai-based militant group Ansar Beit Al-Maqdis in court over 54 separate crimes, including killing police and the attempted assassination of former interior minister Mohamed Ibrahim.
In recent months, militants have increasingly attacked economic targets in urban areas across Egypt, such as electricity pylons and mobile-network stores.
Civilians have often fallen victim during various violent attacks.