The militant group Hasm has claimed responsibility for an attack on a police checkpoint in Maadi, North Cairo, late on Saturday in which a policeman was killed and four others injured.
In a statement published on Sunday on its official social media accounts and website, the militant group claimed the attack, linking it to an Egypt-Saudi maritime border demarcation agreement that places two Red Sea islands within Saudi Arabian territory.
The Hasm statement said the checkpoint attack was "retaliation" for the Egyptian state's "attack on protesters and citizens" who reject the "sale of the land", referring to the islands of Tiran and Sanafir.
On Wednesday, the Egyptian parliament approved the border demarcation agreement, which recognizes Tiran and Sanafir as Saudi sovereign territory. The deal is now awaiting the ratification of President Abdel-Fattah El-Sisi before being implemented.
Hasm has claimed a number of attacks against Egyptian security forces personnel, mostly stationed at checkpoints. Several public figures, such as former grand mufti Sheikh Ali Gomaa, have also been targetted.
Egyptian security bodies say that dozens of Hasm members have been arrested in the past few months. According to interior ministry officials, the group is linked to the Muslim Brotherhood organization. Both groups are designated as terrorist organizations in Egypt.