Militants have reportedly killed 17 people in the north of Egypt’s Sinai peninsula, near the Israel-Gaza border.
Security sources say 15 soldiers and two civilians died when gunmen attacked checkpoints around the town of Sheikh Zuweid on Thursday.
Egyptian forces have been fighting a faction affiliated to the Islamic State group, known as Sinai Province.
Dozens of soldiers and civilians have already been killed this year in northern Sinai.
In the latest incident, gunmen fired on soldiers with automatic rifles and rockets as part of a co-ordinated set of attacks, police officials say.
The army claimed to have killed at least 70 suspected militants in March.
Sinai Province was known as Ansar Beit al-Maqdis until it pledged allegiance to Islamic State leader Abu Bakr al-Baghdadi in November.
It said it was behind most of the major attacks in Sinai, including a series of strikes that left at least 30 people dead on 29 January.
Militants based in Sinai have killed hundreds of soldiers and police since the military overthrew Islamist President Mohammed Morsi in 2013.