An Islamic State affiliate in Egypt has claimed responsibility for a shooting near a historic site just outside Cairo that killed four police.

A statement circulated online by supporters of the group on Sunday vowed to continue targeting the "soldiers of the tyrant," referring to President Abdel-Fattah el-Sissi, who led the military overthrow of Islamist President Mohammed Morsi in 2013.

It was not possible to confirm the authenticity of the statement, but it resembled previous claims issued by the group.

Militant attacks have spiked since Morsi's overthrow, as the government has waged a sweeping crackdown on his supporters and other activists.

Saturday's shooting took place on the outskirts of Cairo near Saqqara, home to the 4,600-year-old Step Pyramid.