At least 26 people have been killed in a series of attacks by Islamist militants in the north of Egypt's Sinai peninsula.
A car bomb and mortars hit military targets in the North Sinai capital El-Arish, killing a number of soldiers.
Other attacks took place in the nearby town of Sheik Zuwayid and the town of Rafah, bordering Gaza.
Militant group Ansar Beit al-Maqdis, which pledges allegiance to Islamic State, said it carried out the attacks.
The insurgents have intensified attacks since Egypt's Islamist President Mohammed Morsi was ousted in 2013.
Tensions have also been raised across Egypt this week amid protests marking the anniversary of the 2011 uprising that ousted then-leader Hosni Mubarak.
Egyptian officials said a car bomb had been detonated outside a military base in El-Arish and mortar rounds were also fired at a military hotel, a police club and more than a dozen checkpoints.
Newspaper al-Ahram said its El-Arish office - which is opposite the hotel and base - had been completely destroyed.
An army major was later shot dead at a checkpoint in Rafah, medical and security sources said.
Another 30 people were also wounded in Thursday's attacks.
North Sinai has been under a state of emergency and a curfew since October when an attack on a checkpoint killed dozens of soldiers.
The army has launched major operations to try to quell violence in the region, but has so far failed.
Ansar Beit al-Maqdis has become the biggest threat, staging many attacks on security targets.
Analysts say Thursday's wide-ranging attacks indicate a previously unseen level of co-ordination.
The group, which was originally inspired by al-Qaeda but later pledged allegiance to Islamic State in Iraq and Syria, has called on Egyptians to rebel against President Abdul Fattah al-Sisi.
President Sisi is the former military chief who led the crackdown on Mr Morsi's Muslim Brotherhood. The Brotherhood has said it rejects violence.
Egypt is creating a 1km (0.6-mile) buffer zone along the border with Gaza in a bid to stop militants smuggling weapons in from the Palestinian territory using tunnels.
The project has displaced more than 1,000 families in Rafah and severed an economic lifeline for many Palestinians.